• Preheat the oven to 425℉. Line a jumbo muffin tray with 8 liners and set aside. Melt the butter and prepare to measure the rest of your ingredients as it cools. Chop the strawberries into small pieces (about 1 cm).
  1/3 cup unsalted butter, 1 1/2 cups fresh strawberries

For the streusel

• With your hands, combine flour, white sugar, and cold cut up butter. Mix together until a crumbly streusel forms. See the photo above for reference. Put into the refrigerator.
  3/4 cup all-purpose flour, 1/3 cup white sugar, 6 tbsp butter

For the muffins

• In a medium bowl, add in flour, salt, cornstarch, baking soda, and baking powder. Stir together and set aside to use later.
  2 1/2 cups all-purpose flour, 2 1/2 tsps baking powder, 1 tsp baking soda, 1/4 tsp salt, 2 tsps cornstarch
• In a large bowl, whisk together all of the wet ingredients. Whisk together for a few minutes until well combined.
  1/3 cup unsalted butter, 1/4 cup oil, 2 large eggs, 1 cup buttermilk*, 1 tbsp vanilla, 1 cup white sugar
• Add the dry into the wet. With a spatula, stir together gently until a soft batter forms. Don't over-mix.
• In the bowl with the chopped strawberries, add 1-2 tsps of flour and gently toss around until the flour is evenly distributed. The light coating of flour will prevent them from sinking to the bottom.
  1 1/2 cups fresh strawberries
• Add the strawberries into the muffin batter and mix in a few times. Don't over-mix!
• Evenly divide your muffin batter between your liners. Make sure they are about 3/4s of the way full max, no more or else they will overflow. This recipe made 8 jumbo muffins for me, but depending on the size of your jumbo pan it can make more or less. Sprinkle a handful of streusel on top.
• Bake the muffins at 425°F for 5 minutes, then turn down to 375°F and bake for 20-25 minutes. Every oven is different, but the muffins are ready a toothpick inserted comes out clean with no wet muffin batter.
• These muffins are best eaten day of or next day. They stay fresh at room temperature for a few days, and in the refrigerator in an airtight container for up to five days.