Chocolate and Vanilla Pinwheel Cookies

Ingredients

  • 1 1/4 cups butter (10 ounces, softened)
  • 1 1/2 cups powdered sugar
  • 1 large egg
  • 1 1/2 teaspoons vanilla
  • 3 cups all-purpose flour
  • 1/4 teaspoon salt
  • 1/4 cup unsweetened cocoa powder