Cream the Butter and Sugar by combining softened butter and granulated sugar using an electric mixer on medium speed for 3–4 minutes until light and fluffy.

Add the Eggs and Vanilla, incorporating large eggs one at a time and mixing until well blended, then add pure vanilla extract.

Mix in Dry Ingredients, sifting all-purpose flour and baking soda gradually into the wet mixture, stirring until no dry flour is visible.

Divide and Color the Dough into five portions, leaving one white and coloring the other four with food coloring.

Spoon the Dough onto a Parchment-lined Cookie Sheet, dolloping the white dough and colored dough alternately.

Flatten and Smooth the Dough, pressing dollops to about 3/4-inch thickness and smoothing the surface.

Bake the Cookie Bars in a preheated oven at 375°F (190°C) for 10–15 minutes until just set.

Cool Completely for about 15 minutes in the pan, then transfer to a wire rack to cool for an hour.

Frost and Decorate the cooled bars with buttercream frosting and optional fall-themed sprinkles.

Slice and Serve, cutting the cooled bars into squares or rectangles.