1-Getting started: Begin by preheating your oven to 350°F and lining a 9×13 inch baking pan with parchment paper. This setup helps the bars release easily and keeps them from sticking.

2-First Steps: Preheat and Mix: In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until they form a light and fluffy mixture. Add the vanilla extract and eggs one at a time, mixing well after each to blend everything smoothly.

Next, in a separate bowl, combine the flour, baking soda, and salt. Slowly add this dry mix to the wet ingredients, stirring until just combined to avoid tough bars.

3-Adding Extras and Baking: Fold in the chocolate chips or chunks for that chocolate sugar cookie bars goodness. If you want a colorful twist, divide the dough and mix in neon food coloring to create swirls.

Spread the dough evenly into your prepared pan and bake for 20 to 25 minutes, until the edges turn golden and the center sets but stays soft. Let them cool completely before cutting and decorating with black icing or melted chocolate for those thematic motifs.