Preheat oven to 350°F.
Line a baking sheet with parchment paper or lightly grease it.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the egg, vanilla and almond extract to the creamed butter mixture, and beat until well combined.
In a separate bowl, whisk together the flour and baking soda.
Add the dry ingredients to the wet ingredients, mixing until just combined.
Gently fold in the Lucky Charms marshmallows and white chocolate chips until evenly distributed throughout the cookie dough.
Using a cookie scoop (#20 size) or spoon, drop rounded 3 tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Top each cookie with a few extra Lucky Charms marshmallows and rainbow sprinkles, pressing them gently into the dough.
Bake in the preheated oven for 8-10 minutes, or until the edges are lightly golden brown.Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.