Preheat the oven to 350℉. Line a cookie sheet(s) with parchment paper, baking mat, or spray with nonstick cooking spray. Set aside.
In a medium bowl whisk together the flour, baking powder, and baking soda. Set aside.
1 cup all-purpose flour, ½ teaspoon baking powder, ½ teaspoon baking soda
In a large mixing bowl using an electric hand mixer, or use the bowl of a stand mixer with the paddle attachment, cream together the butter, sugar, and light brown sugar on medium speed for 3-4 minutes. You want it really fluffy looking and lighter in color.
1/2 cup (1 stick) salted butter, 2/3 cup granulated sugar, 1/3 cup packed light brown sugar
Add in the egg and almond extract. Beat on low speed just until the egg is incorporated.
1 large egg, ½ teaspoon almond extract
Add in the dry ingredients and beat on low speed, increase speed as needed, just until the dough comes together and is combined.
With a rubber spatula, stir in the cornflake cereal, oats, and coconut flakes. * The cookie dough will be thick but should come together when pressed between two fingers. 1½ cups cornflakes cereal, 1 cup whole old-fashioned oats, 1/2 cup sweetened coconut flakes
Use a medium cookie scoop (about 1.5 tablespoons) to scoop the cookie dough out and place 12 cookies per cookie sheet.
Bake for 9-12 minutes or until the edges are barely set and light golden brown.
Remove the cookie from the oven and allow them to cool on the warm baking sheet for 5-10 minutes before removing them to a cooling rack to cool completely.