In a large bowl, cream butter and sugars. Add vanilla and egg, mixing until just barely combined. Continue mixing on medium-low, add flour, salt, baking powder and baking soda. Carefully add remaining wet ingredients, mixing well. With the mixer turned off, add cocoa powder. Mix on low until fully incorporated.

Divide batter among prepared baking liners with one large cookie scoop each.

Bake for 15-18 minutes or until a cake tester comes out clean. Cool on a wire rack.

When cupcakes are completely cool, prepare frosting.

In a medium bowl, beat butter, sugar and vanilla. Add 1 Tbsp milk at a time until spreadable consistency is reached. Frost cupcakes as desired.