1Heat oven to 375º. Mix powdered sugar, butter, vanilla, egg and food colors in large bowl with spoon. Stir in 1 1/4 cups of the Bisquick mix. Shape dough into a ball. Sprinkle remaining 1/4 cup Bisquick mix on countertop or other hard surface. Roll ball of dough in Bisquick mix. Knead dough 10 times.
2Divide dough into 10 pieces. Roll each piece into 6-inch log, using lightly floured hands. Place about 2 inches apart on ungreased large cookie sheet.
3Bake 6 to 8 minutes or until set. Cool 2 minutes; remove from cookie sheet to wire rack. Cool completely, about 15 minutes. Cut each strip crosswise in half. Spread frosting over rounded ends of cookies to look like fingernails. Drizzle gel over cut ends of cookies to look like blood.