Step 1: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Step 2: In a medium-sized bowl, whisk together the all-purpose flour, baking powder, and baking soda. Set aside this dry mixture.

Step 3: In a large bowl, use an electric mixer to cream the softened butter, brown sugar, and granulated sugar together until the mixture becomes light and fluffy. This should take about 2-3 minutes.

Step 4: Add the eggs one at a time to the butter mixture, mixing well after each addition. Then, stir in the vanilla extract and continue mixing for an additional 2 minutes until fully combined.

Step 5: Slowly add the dry flour mixture to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.

Step 6: Gently fold in the rolled oats, Rice Krispie cereal, and semi-sweet chocolate chips. Make sure that the ingredients are evenly distributed throughout the dough for a consistent flavor and crunch in every bite.

Step 7: Use a cookie scoop or tablespoon to form dough balls and place them onto the prepared baking sheet. Leave about 2 inches of space between each cookie to allow them to spread as they bake.

Step 8: Bake the cookies for 9-10 minutes, or until the edges begin to turn a light golden brown. Avoid overbaking; the cookies will firm up as they cool.

Step 9: Remove the baking sheet from the oven and let the cookies cool for a few minutes before transferring them to a wire rack to cool completely. This cooling process helps the cookies maintain their soft centers while the edges stay crisp.