In another large bowl, whisk in the wet ingredients. Whisk until well combined.
3/4 cups dark brown sugar*, 1 tbsp vanilla, 1/2 cup oil, 2 large eggs, 3/4 cups full-fat sour cream, 1/2 cup milk
Add the dry into the wet and with a spatula, gently mix together until a soft batter forms.
Evenly divide the batter between 12 liners, they should be almost or all the way full. Using a cookie scooper helps big time to minimize the mess. In a small glass, mix together cinnamon and sugar. Then sprinkle a bit on top of each muffin.
1/4 tsp cinnamon, 2 tbsp white sugar
Bake the muffins at 425℉ for 5 minutes, then lower the oven to 375°F (don't open the oven door) and continue baking for 15-20 minutes. The muffins are ready when a toothpick inserted comes out clean.
These muffins stay fresh at room temperature for up to 3 days, and in an airtight container in the refrigerator for up to a week!
Notes
*Brown sugar - This recipe is not meant to be sweet, it is more of a breakfast-style muffin. If you are looking to sweeten them up, add in 1/4 cup (50g) more of brown sugar.