1-Getting Started: First, preheat your oven to 350°F (175°C) and grease your pan with the extra softened butter. This ensures your big chocolate chip cookie birthday cake bakes evenly and slides out easily once it’s done.

2-Mixing the Batter: In a medium bowl, whisk together the 2 1/2 cups all-purpose flour, 1 teaspoon baking soda, 1/2 teaspoon baking powder, and 1/2 teaspoon kosher salt. This step helps distribute the leavening agents evenly for a fluffy texture.

Now, in a large mixing bowl, cream the 1 cup softened unsalted butter with 3/4 cup granulated sugar and 1 1/3 cups packed light brown sugar until it’s light and fluffy. Beat in the 2 large cold eggs one at a time, then add the 2 teaspoons vanilla extract to boost the flavor.

3-Combining and Baking: Gradually mix the dry ingredients into the wet mixture until just combined, then fold in the 1 cup chocolate chips. Pour the batter into your prepared pan and smooth the top.

Bake for 25-30 minutes, or until a toothpick comes out clean. Let it cool for 10 minutes before decorating with vanilla or chocolate buttercream frosting and assorted sprinkles.