Preheat the oven to 350°F and line a baking sheet with parchment paper.
In a large mixing bowl, cream together the butter and sugar until well combined. Add the egg and vanilla extract, and beat until smooth.
Add the flour, baking soda, baking powder, and salt. Mix until a dough forms. If the dough is too crumbly, add 1 tablespoon of melted butter to help bring it together.
Divide the dough evenly into three portions. Leave one plain, and tint the others with red and blue food coloring, mixing each until the color is fully incorporated.
Take about 1 tablespoon of dough from each color and gently roll them together to form a tie-dye effect.
Roll each cookie ball in granulated sugar, then place them on the prepared baking sheet.
Bake for 10–12 minutes, or until the edges are lightly golden. The centers should be soft.
Remove from the oven and allow the cookies to cool on the baking sheet for a few minutes before transferring to a wire rack.
Notes
To intensify the color, use gel food coloring.
To preserve the tie-dye pattern, avoid overmixing after combining the colors.
Keyword Red, white and blue tie dye cookies for 4th of July