Preheat your oven to 350°F (175°C). This step is essential to ensure your cookies bake evenly and achieve that perfect golden brown finish.

Whisk together the dry ingredients: in a bowl, mix the all-purpose flour, baking soda, baking powder, and salt until fully combined.

Cream the butter and sugars: in a separate large bowl, beat the room temperature unsalted butter, granulated sugar, and light brown sugar together until creamy.

Add the egg and vanilla extract: incorporate the large egg and vanilla extract into the butter mixture, mixing well until combined.

Combine the dry ingredients with the wet: gradually add the flour mixture to the butter mixture, mixing until just combined.

Color your dough: add drops of green, orange, and purple gel icing color to the dough, mixing until vibrant.

Fold in the M&Ms: gently stir in your choice of M&Ms.

Scoop the dough: portion out the cookie dough onto baking sheets, spacing them about 2 inches apart.

Bake in the preheated oven for about 10-12 minutes or until edges are golden brown.

Cool on a wire rack: let cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack.