1-First Step: Preheat and Prep Your Pan: Heat oven to 350°F. Grease a 9-inch round cake pan or line with parchment for easy release. This prevents sticking and ensures clean slices. Gather all tools: mixer, spatula, measuring cups. Mise en place saves time, especially for busy schedules.

2-Second Step: Cream the Butter and Sugars: In a large bowl, beat ½ cup softened butter, ½ cup brown sugar, and ¼ cup white sugar. Mix 2-3 minutes until light and fluffy. This step traps air for a tender crumb. Scrape sides often. Tip: Room-temp butter blends smoother than melted.

3-Third Step: Add Wet Ingredients: Beat in 1 egg and 1 tsp vanilla extract until combined. The egg adds lift, vanilla brightens taste. Mix just 1 minute to avoid overworking. If batter looks curdled, keep going, it smooths out.

4-Fourth Step: Incorporate Dry Ingredients: In a separate bowl, whisk 1 cup flour, ½ tsp baking soda, and ¼ tsp salt. Gradually add to wet mix on low speed. Stir until no dry spots remain, but do not overmix. Dough will be thick.

5-Fifth Step: Fold in Chocolate Chips: Gently fold in 1 cup chocolate chips with a spatula. Reserve a handful for topping. This distributes melty bits evenly. Pro move: Chill dough 10 minutes for thicker cookies.

6-Sixth Step: Spread and Bake: Press dough evenly into prepared pan using wet hands or offset spatula. Sprinkle extra chips on top. Bake 20-25 minutes. Edges golden, center soft with slight jiggle. Cool in pan 10 minutes, then on rack fully. Overbaking dries it out, so timer is key.

7-Seventh Step: Make and Apply Frosting: Whip ¼ cup butter, 1 cup powdered sugar, 1 tsp vanilla, and 1-2 tbsp milk until fluffy. Pipe borders with star tip or spread edges. Add sprinkles. Chill 15 minutes to set. Slice with sharp knife dipped in hot water.