Dark Chocolate Valentine's Day Cookies

2 cups all-purpose flour 1/3 cup Hershey's Special Dark Cocoa powder1 teaspoon baking powder1 cup unsalted butter, softened 1/2 cup granulated sugar 1/2 cup light brown sugar, packed1 large egg2 teaspoons vanilla extract1 egg white, slightly beatenRed colored sanding sugars, sprinklesHeat oven to 350 degrees. Line 2 large baking sheets with parchment paper or lightly grease. Set aside large, heart-shaped cookie cutters.In medium bowl, stir together flour, cocoa powder and baking powder. Set aside.In large bowl, beat butter and sugars on medium speed for 1 minute. Add egg and vanilla. Beat 2 minutes on high speed until light and fluffy. Scrape bowl well.Add half flour mixture and mix on low speed until combined. Gently stir in remaining flour mixture until combined. Scrape bowl well. Using lightly damp hands, press dough ball together. Flatten into 2 small disks. Cover with plastic wrap and chill 1 hour.Roll out each dough disk until 1/4-inch thick. Cut cookies close together with heart-shaped cutters. Place 2 inches apart on baking pans. Brush with beaten egg white. Sprinkle with colored sugars and bake 10 to 11 minutes. Do not over bake. Cool cookies 10 minutes before transferring cookies to rack. Cool 30 minutes before plating or packaging cookies.Makes about 20 cookies.Baker's hint: For a choco-berry flavor, substitute raspberry or cherry liqueur for the vanilla extract.Nutrition values per serving: 169 calories, 10 g fat (6 g saturated fat), 19 g carbohydrates, 1 g fiber, 2 g protein, 36 mg cholesterol, 34 mg sodium.