Step 1

Preheat the oven to 425°

Step 2

Line a muffin tin with liners or grease the tin well.

Step 3

In a large bowl, beat together the softened butter, granulated sugar, and the brown sugar.

Step 4

Add in the vanilla extract and eggs, mix.

Step 5

Beat in the sour cream until it is well blended.

Step 6

Add in the salt, baking powder, and baking soda.

Step 7

Blend the flour, careful not to overbeat.

Step 8

Add in the milk until mixed.

Step 9

Add 1 tsp of batter to 12 liners. Set aside.

Step 10

Mix together the melted butter, brown sugar, cinnamon, cocoa, salt, and flour.

Step 11

Combine until the mixture is crumbly

Step 12

Add a tsp of the mixture on top of the batter inside the muffin tins.

Step 13

After sprinkling 1 tsp of the mixture to the tins, fill the liners with the remaining batter all the way to the top. Gently press into the muffin batter.

Step 14

Sprinkle the rest of the crumb mixture

Step 15

Bake in the preheated oven at 425° for 5 minutes.

Step 16

Reduce the temperature to 350° and bake for 12-13 minutes.

Step 17

Remove from the oven and let cool on a wire rack.

Step 18

Combine 2 tbsp of milk, ½ tsp of vanilla, and ½ cup of confectioner's sugar.

Step 19

Drizzle the glaze on the crumb topping once the muffins are completely cool.

Step 20

Store in an airtight container.