1 cup unsalted butter, softened
1 egg white—whipped
2 teaspoons pure vanilla extract
2 1/2 cups all-purpose flour
1 1/2 cups sugar
1 1/2 teaspoons baking powder
1 teaspoon red food coloring
1 teaspon blue food coloring
In a mixing bowl, combine butter, egg white and vanilla extract.
In a separate bowl, combine flour, sugar and baking powder. Mix wet ingredients with dry until just moistened. Divide cookie dough into three equal portions. Tint 1 portion with the red food coloring and another portion with the blue food coloring. Mix thoroughly. Form each portion into long bars and stack bars on top of each other using alternating colors (red, white, blue).
Wrap finished cookies in waxed paper and place in the refrigerator for about an hour. Cut cookies into 1/4 inch thick bars.
Preheat oven to 350 degrees F.
Place on greased baking sheet and bake for 10 to 12 minutes.