Preheat oven to 350 degrees. Prepare a baking sheet with parchment paper.

Whisk together dry ingredients: flour, baking powder, and salt. Set aside.

In a mixing bowl, blend the butter and sugar until creamy and light. Add egg and vanilla extract. Mix well. Slowly add dry ingredients and mix until combined. Dough may be a little crumbly.

Turn out the dough onto a surface sprinkled with powdered sugar or flour. Divide into 6 equal parts.

Add food coloring to each portion of dough and return to the mixer until completely blended. Repeat with each color.

Flatten each color of cookie dough into a rectangle shape and layer onto one another, creating a stack of cookie dough. Press together with a rolling pin and flatten to about ¼ to ½ inch thickness.

Starting on the largest side, roll the cookie dough into a tube (like a jelly roll) pressing any cracks to keep the roll tight.

Slice into ¼ to ½ inch slices. Place on a parchment-lined baking sheet.

Bake cookies for 7 to 9 minutes. Do not brown the cookies. Allow cookies to cool for at least 20 minutes on the baking sheet before carefully removing to a cooling rack.