4teaspoons red food coloring(I used gel food color)
2 1/2cupsall-purpose flour
3tablespoonsunsweetened baking cocoa powder
Vanilla Buttercream Frosting
1/2cupunsalted butterroom temperature
1tablespoonheavy cream (or milk)
Preheat oven to 350 degrees F and line a cookie sheet with parchment paper.
In the bowl of an electric mixer (or using a hand mixer), cream together butter and sugar until light and fluffy (about 2 minutes).
Add sour cream, egg, and food coloring. Mix to combine.
In a separate mixing bowl, combine flour, baking powder, cocoa powder, and salt.
Mix in dry ingredients to wet ingredients and stir until just combined.
Roll dough into 1-inch balls. Press your thumb into the center of each ball to leave an indention. Bake for 10-12 minutes. Allow to fully cool.
To make frosting, using an electric mixer, beat butter, powdered sugar, heavy cream, and vanilla extract until light and fluffy (3-5 minutes). Use a piping tip to add a swirl of frosting to the center of each thumbprint cookie.
If frosting is too loose, add more powdered sugar. If it's too thick, add more cream (or milk).