This banana sour cream coffee cake is packed with so much deliciousness! Every bite has a tender buttery crumb, lots of banana flavour, and a cinnamon sugar streusel. It’s the perfect way to start the day.

Relax with a slice of this soft and fluffy coffee cake!
The cake comes together in one bowl and is super moist thanks to the sour cream used. It’s layered with a buttery cinnamon sugar streusel, baked, and then drizzled with a vanilla icing that brings it all together!
Pair this with a cup of coffee and you’ll be ready to take on the day!
For more cake recipes, try Apple Pumpkin Crumble Cake, Carrot Cake Cheesecake Bars, and Easy Chocolate Sheet Cake.
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Why this recipe works
Bananas - A great way to use up leftover bananas!
Coffee cake - A delicious and simple way to start the day.
Easy cake – This recipe uses simple ingredients you most likely already have!
Streusel – Only 4 ingredients needed for the streusel layer!
Ingredients Notes
Scroll to view a few ingredients notes. Full recipe and measurements can be found in the recipe card below.
Brown sugar – Used both in the streusel and in the cake. I like to use dark brown, but light works too.
Eggs – Remove two hours before baking.
Flour – I used all-purpose flour for this recipe.
Bananas - Ripe, fresh bananas are used. The riper and more brown spots, the better. This means your cake will be sweeter. If using frozen, drain the liquid before mashing and measuring.
Sour cream – Adds richness to the cake. Plain full fat yogurt works as well. Remove two hours before baking.

Step by step instructions
Here is how to make and bake this Banana Sour Cream Coffee Cake. You will need an 9x9 square pan lined with parchment paper, a large mixing bowl, a spatula, and a whisk.
Step 1 – Prep. Preheat the oven to 350°F/175°C and line and grease a 9x9 inch square pan. Mash the bananas and melt the butter and set aside.
Step 2 – Make the streusel. In a small bowl, add brown sugar, cinnamon, and cold butter. Mix with a fork until a wet clumpy sand texture forms. Set in the fridge while you make the batter.

Step 3 - Mix dry ingredients. In a large bowl, add flour, baking soda, baking powder, and salt. Mix until combined and set aside.
Step 4 – Whisk wet ingredients. In a large bowl, whisk butter and brown sugar. Then add in egg, vanilla, bananas, and sour cream. Whisk until well combined.


Step 5 - Combine. Add the dry into wet and mix until JUST combined. Don't over-mix!


Step 6 – Layer. Add half of the batter into your prepared pan and spread evenly. Then sprinkle roughly half of the streusel on top. Add the remaining half of your batter evenly, and then the rest of your streusel on top again.


Step 7 – Bake. Bake the cake for 35-45 minutes, or until a toothpick inserted comes out dry. If it is wet, then the cake hasn’t fully baked yet so continue to bake at 5 minute intervals. Allow it to cool completely.
Step 8 – Make glaze. When the cake is cooled, make your glaze by mixing together icing sugar and vanilla. Drizzle, allow to set, slice, and enjoy!

Expert Baking Tips
Here are a few expert baking tips from my kitchen to yours
- When I say cool the butter, I mean back down to room temperature after melting. It should still be liquid when whisking. Don’t refrigerate this to speed it up or else it’ll solidify.
- Speed the process of cooling the butter down by placing the glass measuring cup of butter into a bowl of cold water. Think of it like a double boiler method, but cooling instead of heating.
- Make sure all of your wet ingredients are at room temperature. It’s important or else the ingredients won’t work the way we want them too together.
FAQ
Why isn’t there any coffee in this cake?
Coffee cake actually doesn’t have any coffee in it! It’s meant to be paired with a cup of coffee.
Why is there sour cream in this cake and can I taste it?
You cannot taste it at all. Using sour cream in cakes creates a superrrr soft and tender cake. It is what fluffy dreams are made of. If you don’t have any sour cream on hand, use full fat plain yogurt instead.
Do I have to add bananas?
Yes! The bananas are mandatory and cannot be substituted.
Can I double this recipe?
Absolutely! Bake it in a 9×13 pan and keep an eye out for the time as it’ll most likely bake longer than in an 9x9 pan.
Can I use white sugar instead?
No, you have to use brown sugar in this recipe!
Storing
Once cooled, drizzled, and the icing has set, slice this cake into 9 even squares.
I recommend making it the day of if you are bringing it to a dinner party as it is best served fresh.

Check out these recipes

Banana Sour Cream Coffee Cake
Ingredients
For the cake
- 1 3/4 cups all purpose flour
- 1 tsp baking powder
- 1 tsp baking soda
- 1 tsp cornstarch
- 1/2 tsp salt
- 1/2 cup light brown sugar
- 6 tbsp unsalted butter melted
- 2 tbsp oil
- 1/2 cup sour cream room temperature
- 1 large egg room temperature
- 1 tbsp vanilla
- 3/4 cups bananas mashed, about 2 medium sized
For the streusel
- 8 tbsp butter cold and cubed
- 2 tsps cinnamon
- 1 cup all-purpose flour
- 3/4 cups light brown sugar
For the icing
- 1/2 cup powdered sugar
- 1 tbsp vanilla or milk
Instructions
- Line a 9x9 inch square metal pan with parchment paper and set aside. Preheat the oven to 350℉. Mash the bananas and set aside. Melt the butter and as it cools, prep the rest of your ingredients.3/4 cups bananas, 6 tbsp unsalted butter
- In a small bowl, add the butter, cinnamon, flour, and sugar and mix with a fork or your hands until a wet sand texture forms. I recommend using your hands for this step! This will be your streusel. Set it aside.8 tbsp butter, 2 tsps cinnamon, 1 cup all-purpose flour, 3/4 cups light brown sugar
- In a large bowl, add flour, baking soda, baking powder, cornstarch, and salt. Mix together and set aside.1 3/4 cups all purpose flour, 1 tsp baking powder, 1 tsp baking soda, 1/2 tsp salt, 1 tsp cornstarch
- In a large bowl, whisk melted and cooled butter, oil, brown sugar, bananas, egg, vanilla, and sour cream until smooth.1/2 cup light brown sugar, 6 tbsp unsalted butter, 1/2 cup sour cream, 1 large egg, 1 tbsp vanilla, 2 tbsp oil
- Add the dry ingredients. Using a spatula, gently fold until a soft batter forms. Do not overmix!!!
- Spoon half of the batter into the prepared pan. Sprinkle with half of the streusel. Spread the remaining batter over the streusel. Then finish by sprinkling the remaining streusel.
- Bake for 35-45 minutes or until a toothpick comes out clean. Mine took 42 minutes exactly!
- Once cooled, make the glaze by mixing together the icing sugar and vanilla (or milk). Drizzle, allow it to set, and enjoy!1/2 cup powdered sugar, 1 tbsp vanilla
Lisa Lockett says
I am in the middle of making this recipe. And yes, I had someone else read the recipe to be sure, the ingredients do not say anything about milk for the base. BUT!! In the directions, it says to add milk to it. So, how do I finish this??
Ania says
Hi Lisa! There is no milk in this banana sour cream coffee cake, I apologize for the confusion. However, there is milk in the icing if you decide to make it! Hope this clarifies everything - enjoy the cake!
Denise says
I made this for the first time a few days ago. We really enjoyed it, especially after it had sat for a few days. The banana flavor seemed more pronounced than the morning after I baked it. We also are struesel snobs and always double the amount in a recipe. After preparing the ingredients for this struesel, I realized it was going to be plenty! I definitely will be baking this again with my "too old" bananas.
Ania says
Hi Denise! I'm so glad to hear you and your family loved the banana sour cream coffee cake. My family is also obsessed with streusel, it's the best! Luckily streusel freezes well so any extra you have can go into a ziplock bag for next time 😉 Happy baking!
Lisa Lockett says
Just made this again!! Omg!! So, so delicious!!
Ania says
Hi Lisa!! I'm so happy!! Thank you for sharing yay enjoy 🙂
Catherine A Sis says
This cake was a huge hit with the whole family. Banana flavor was very good. I also enjoyed the instructions with ingredients at each step. I always prep all ingredients before starting and the extra information when baking was greatly appreciated along with choice of metric. The streusel was amazing. I thought at first it would be a little to much but it was perfect. Everyone in family wants this on a regular rotation.
Ania says
Hi Catherine! I am so so happy to hear the cake was a hit with your family! Thank you for sharing your comment, it made my day! Happy baking 🙂
Beth says
I really like this cake and the instructions were very easy, especially the tips on cooling the melted butter and taking out the egg and sour cream to get to room temperature. However, I did not like the icing glaze. The vanilla was too bitter. Next time I will use milk.
Ania says
Hi Beth! Thank you for your comment I appreciate it. I'm happy to hear you enjoyed the coffee cake and hope the icing tastes better for you with milk next time! Thank you for sharing 🙂
Mary says
Made this today & it is delicious. Made the icing with vanilla & it tastes great!
Ania says
Amazing!! So happy to hear the cake was delicious, thanks for sharing Mary 🙂
S. ESTRADA says
I noticed cornstarch on the recipe list of ingredients but it is not mentioned at what point to add in. Does it go with the dry ingredients for the batter?
Ania says
Hi! The cornstarch is added into the dry ingredients. Enjoy the cake 🙂
Yvette says
If I want to use 8.5"x 4"9/16x 2"3/4 loaf pan how to ensure I have enough batter?
Jody says
When baking i always weigh flour at 120g/cup. I've never seen it posted at less than 120g. The metric for this recipe shows 187g of flour total but for 1 3/4 cups that doesn't make sense to me. I believe it should be 120g + 90g = 210g
Could u clarify this please? Thanks.
Ania says
Hi Jody, thank you for your comment. I’m not sure why the metric came up as 187g (the grams convert automatically from Google), but I measure 1 cup at 125g. So it should be 218g. I will go in and manually change this. Great catch, and thank you for pointing it out to me! Enjoy the cake 😊