01 -
Cream the softened butter with the light brown sugar and granulated sugar until smooth and fluffy.
02 -
Mix in the egg yolk, vanilla extract, and red gel food coloring until evenly combined.
03 -
Sift together the flour, cocoa powder, baking powder, and salt; then gradually mix into the wet ingredients until a dough forms.
04 -
Scoop the dough by tablespoons into 18 equal portions, roll each into a ball, and coat thoroughly with red sanding sugar.
05 -
Place coated dough balls on a baking sheet, 1.5 inches apart, and bake at 350°F (177°C) for 10 to 12 minutes until edges are set but centers remain soft.
06 -
Immediately remove from the oven and gently press one Hershey's Kiss into the center of each cookie; allow to cool completely on the baking sheet.