These light, tender Coffee Cake Muffins are perfect for breakfast, brunch, or a coffee date. Or right now!
Make the streusel by combining dark brown sugar, cinnamon, walnuts and melted butter. Set aside.
Combine the dry ingredients and set aside. In a medium bowl, whisk together the melted butter, egg and sour cream.
Add butter, egg and sour cream mixture to the dry ingredients, and fold together until just combined.
Fold in HALF of the streusel topping to the batter. Divide the batter between the muffin cups. Top muffins with remaining streusel topping.
Bake for 20-25 mins. Remove from oven when a toothpick inserted in the middle of a muffin comes out clean. Cool on wire racks. Devour.