Preheat the Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
Mix Dry Ingredients: In a bowl, mix together the flour, baking powder, and baking soda. Set aside.
Cream Butter and Sugars: In a large bowl, cream the softened butter with the brown sugar and granulated sugar until light and fluffy.
Add Eggs and Vanilla: Mix in the eggs and vanilla extract until well combined.
Combine Wet and Dry Ingredients: Gradually add the dry ingredient mixture to the wet ingredients, mixing until just combined.
Fold in Mix-ins: Gently fold in the rolled oats, Rice Krispies, and chocolate chips.
Form the Cookies: Scoop spoonfuls of cookie dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake: Bake for 9-10 minutes, or until the edges are golden. Allow the cookies to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.