Begin by creaming the butter in a large bowl or stand mixer.
Add the sugar and mix until well incorporated.
Next, add the egg, baking powder and vanilla. Mix until all of the ingredients have been combined.
Begin adding flour about a ½ cup at a time mixing in between ½ cups. Dough should begin to be pliable but not sticky. If it is sticky gradually add a tablespoon of flour at a time.
Divide the dough into 3 equal parts. Leaving one part uncolored, add pink and purple to the other 2 sections of dough(one pink and one purple).
Place the dough in the refrigerator for about 15 minutes.
When the dough is firm, roll each section to be about ½ inch thick.
Once rolled out stack the dough on a piece of plastic wrap with orange on the bottom, yellow in the middle and the uncolored on top. Cut the edges so the dough so it is a rectangle.
Roll up the dough into a log and place in the freezer for about 10 minutes or the refrigerator for about 40 minutes.
10. Preheat the oven to 350º F. When the dough is firm enough, remove the plastic wrap and begin cutting the long into about ½ inch pieces*.
11. Place the cookies on a parchment lined cookie sheet. Bake 8-10 minutes then let cool on a cooling rack before enjoying.
Notes
*In similar recipes it is suggested to use thread or a very thin sharp knife. I however have a cheese board with a wire cutter that works perfectly. Use whichever you desire.