- 1/2 cup granulated sugar
- 2 tablespoons confectioner's sugar
- 1/4 teaspoon salt
- 1 egg
- 1 teaspoon vanilla extract
- 1 cup unsalted butter, room temperature
- 2 cups all-purpose flour
- Rainbow food coloring
- Combine the granulated sugar, confectioner's sugar and salt in a bowl. In a separate bowl, combine the egg and vanilla extract. Set both bowls aside.
- Beat the butter with an electric mixer until pale and fluffy. Add the sugar mixture and mix until combined. Add the egg mixture and combine. Gradually add the flour and mix until just combined.
- Divide the dough into 2 balls, and set one ball aside. Divide the other ball into 6 pieces and dye each piece a color of the rainbow.
- Sandwich the beige dough between 2 sheets of floured parchment paper and roll out into a 10x12-inch rectangle. Roll each colored ball of dough into a sausage shape and line them up on another sheet of floured parchment paper. Make sure to line them up so that the long edges only have one color of dough and the short edges show all 6 - this will create the rainbow pattern when rolling the dough later. Gently press together and place another sheet of floured parchment paper on top. Roll out into a 10x12-inch rectangle. Stack the sheets on a baking sheet and place in the fridge for 1 hour.
- Remove the top sheet of parchment paper from both sheets of dough and flip the rainbow dough on top. Trim the edges. Position the dough with the long edge facing you and roll the dough away into a spiral. Roll the dough tightly in plastic wrap and place in the freezer for 1 hour.
- Slice the dough into 1/4-inch-thick slices and place on a baking sheet lined with parchment paper. Bake at 325°F for 14 minutes, until the edges are just slightly golden. Cool completely and enjoy!