Prepare the Fresh Strawberry Frosting and place into the fridge. Preheat the oven to 350 degrees F and line a standard muffin tin with paper liners. Set aside.
In a medium bowl, beat the butter and sugar with a handheld electric mixer until light and fluffy, about 1 minute. Add the eggs, one at a time, then the sour cream, vanilla, and milk. (You can also use a blender for that part.)
Slowly add in the flour, cocoa powder, baking powder, baking soda, and salt. Stir gently until just combined.
To make more modest sized cupcakes for younger kids: Fill prepared paper liners about � full. Bake for 14-16 minutes, or until a cake tester inserted into the center comes out cleanly.
To make more standard size cupcakes: Fill 9 cupcake liners with about � cup batter. Bake for 16-18 minutes, or until a cake tester inserted into the center comes out cleanly.
Remove from oven. Remove cupcakes from pan and let cool completely on a wire rack.
Just before serving, remove the frosting from the fridge. Snip off one corner of the bag and pipe onto cooled cupcakes. Garnish with a slice of berry, if desired, and serve immediately.
