• Preheat the oven to 350°F. Line two muffin tins with paper liners and set aside.

Cookie dough

• In a medium bowl, cream together the 1/2 butter and brown sugar until light and fluffy. Add in the egg and 1 tsp vanilla, and mix until fully combined. Mix in the 1 1/3 cup flour, baking soda and salt until fully incorporated.
• Using a medium cookie scoop (around 1.5 Tablespoons), scoop the cookie dough into the bottom of the muffin cups, and press down with the back of a spoon.

Cupcakes

• In a medium bowl, cream together the 1/2 cup butter and white sugar until light and fluffy. Add in the 2 eggs and 1 Tbs vanilla until fully combined.
• In a separate bowl, mix together the 1 1/2 cup flour and baking powder.
• Alternate between mixing in the flour mixture and the milk into the wet ingredients, starting and ending with the flour.
• Divide the batter evenly on top of the cookie dough, and bake in the preheated oven for 18-23 minutes, or until a toothpick inserted comes out clean.

Frosting

• In a medium bowl, cream the butter until smooth and creamy. Slowly add in the powdered sugar, and mix until combined. Add in the 1 Tbs vanilla, and mix until fully incorporated. If the frosting is too thick, add in the milk.