This recipe is from In Katrina's Kitchen. I altered it very slightly to account for using fondant hearts (I had them on hand) and a longer baking time.
GRINCH COOKIES
INGREDIENTS
1 box vanilla cake mix
1/2 cup vegetable oil
2 eggs
1 drop green food coloring
Powdered sugar
Heart-shaped fondant pieces, sprinkles, or candies
DIRECTIONS
Preheat oven to 350F.
Combine cake mix, food coloring, oil, and eggs in stand mixer bowl.
Chill the dough for 10-15 minutes.
Roll into tablespoon-size balls and roll in powdered sugar.
Place on baking sheet and press one large heart fondant/candy/sprinkle in center.
Bake for 8-10 minutes or until cracked. Remove one cookie from the oven and split in half to check the cookies are thoroughly baked. If not, continue baking for another 2-3 minutes.
Let cool two minutes on pan before removing to cool completely on a wire rack.