Preheat oven to 425°F and line a jumbo muffin pan with baking cups or lightly grease with nonstick spray.
Make the streusel topping by mixing together the flour, brown sugar, cocoa powder, and melted butter (a spatula works best).Set aside to dry while making the muffin batter.
In a large bowl, whisk together the flour, sugar, baking powder, salt, and instant coffee granules.
In a medium bowl, whisk together the eggs, kefir, vegetable oil, and vanilla extract.
Gently stir the wet ingredients into the dry ingredients just until the flour streaks disappear.
Fill the muffin liners with batter and then sprinkle the streusel topping over them.
Bake at 425°F for 5 minutes. Without opening the oven, reduce the temperature to 375°F and bake until a toothpick comes out clean (about 15 more minutes, for a total bake time of 20-25 minutes).
Once the muffins are cool enough to touch, transfer them to a wire cooling rack.
Notes
Storage: Store cooled cappuccino muffins at room temperature for 5 days or in the freezer for 2 months.Mini Muffins: Bake at 350°F for about 10-15 minutes.Regular Muffins: Fill regular muffin liners ¾ full and follow the same baking instructions as written. They make take less time to bake.Lifeway Kefir: This recipe is sponsored by Lifeway Foods. All opinions are my own and I genuinely love their products and mission! If you can't find their kefir, you can substitute it with an equal amount of buttermilk.