Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

In a medium mixing bowl, whisk together 2 ½ cups of all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, and ½ teaspoon salt.

In a large bowl, cream ¾ cup softened unsalted butter, ½ cup granulated sugar, and ¾ cup brown sugar until light and fluffy, about 3–4 minutes.

Beat in 1 large egg and 1 teaspoon vanilla extract until well blended, about 1 minute.

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined.

Gently fold in 1 cup pastel M&M’s and ½ cup white chocolate chips using a spatula.

Using a cookie scoop, drop 1½ to 2½ tablespoons of dough onto the prepared baking sheets, leaving about 2 inches of space between each mound.

Place the baking sheets in the preheated oven and bake for 8–11 minutes.

Remove the cookies from the oven and let cool on the baking sheets for about 5 minutes.

After cooling completely, transfer your cookies to an airtight container.