1-First Step: Preheat your oven to 350°F and grease a 12-inch pizza pan or springform pan with butter or non-stick spray. This prevents sticking and ensures easy release. Gather all ingredients at room temperature for smooth mixing; cold butter leads to lumps.

2-Second Step: In a large bowl, beat 1 cup softened butter and 1 ½ cups sugar with an electric mixer for 2 minutes until light and fluffy. This creaming process traps air for tenderness. Scrape down sides to incorporate fully.

3-Third Step: Add 1 egg and 2 tsp vanilla extract. Beat on medium speed for 1 minute until smooth and pale. The egg adds moisture, while vanilla brightens the flavor profile.

4-Fourth Step: In a separate bowl, whisk together 2 ½ cups flour, 1 tsp baking soda, and 1 tsp salt. Gradually add dry mix to wet ingredients on low speed. Mix just until combined, about 1 minute, to avoid tough dough. Dough should be soft and slightly sticky.

5-Fifth Step: Cover dough and chill in fridge for 30 minutes. Chilling firms it up, preventing excessive spreading during bake. This step is key for thick, chewy cookies.

6-Sixth Step: Press chilled dough evenly into prepared pan, creating a ½-inch thick layer. Use wet fingers or spatula for smooth edges. Aim for uniform thickness to bake evenly.

7-Seventh Step: Bake at 350°F for 18-25 minutes. Edges turn light golden brown while center stays soft. Rotate pan halfway for even browning. Overbaking dries it out; start checking at 18 minutes.

8-Eighth Step: Remove from oven and cool in pan on wire rack for 10 minutes, then transfer to rack to cool completely, about 1 hour. Warm frosting melts, so patience pays off.

9-Ninth Step: Prepare buttercream by beating ½ cup softened butter, 2 cups powdered sugar, 1 tsp vanilla, and 2-3 tbsp heavy cream until fluffy. Spread over cooled cake.

10-Final Step: Add sprinkles, chocolate chips, or piped messages. Chill 30 minutes to set. Slice into 12-16 wedges and serve. Store as detailed later. This sugar cookie cake method yields bakery-quality results at home.