Start by whisking together the flour and salt in a medium bowl.
In a separate large bowl, cream the softened butter and sugar until it’s light and fluffy—this is where the magic begins! Beat in the egg and vanilla extract, and then gradually add the dry ingredients until a lovely dough forms.
Now, divide the dough into three equal parts. Keep one part plain for the white dough, and color the second part red and the third part green using your gel food coloring. Knead the dough until the colors are vibrant and evenly distributed. Once that’s done, wrap each colored dough in plastic wrap and pop them in the fridge to chill for about 30 minutes.
Roll out the white and red dough separately to about 1/4 inch thickness.
Cut each into long, even strips, then alternate layering the red and white strips to create a candy cane stripe effect. Gently press them together to seal. Roll this layered dough slightly to smooth out the stripes and even the surface.
Using a round cookie cutter, cut circles from the striped dough, and then use a smaller Christmas tree-shaped cutter to cut out the center of each striped cookie.
Roll out the green dough and cut out small trees using a mini Christmas tree cutter. Place a green Christmas tree cutout in the center of each round striped cookie, filling the space beautifully.
Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Arrange the cookies on the prepared sheet and bake for 8-10 minutes, or until the edges are lightly golden. Once baked, let them cool completely on a wire rack.