Candy Bar Blondies

Preheat your oven to 350 degrees Fahrenheit. Grease a 9x13 inch baking pan with butter or non-stick cooking spray, then line it with parchment paper, allowing some overhang on the sides for easy removal.
In a large mixing bowl, use an electric mixer on medium speed to cream together the softened butter and packed brown sugar until the mixture is light, fluffy, and well-combined, about 2-3 minutes.
Beat in the eggs one at a time, followed by the vanilla extract, scraping down the sides of the bowl as needed to ensure everything is fully incorporated.
In a separate medium bowl, whisk together the flour, baking powder, and salt. Gradually add these dry ingredients to the wet ingredients, mixing on low speed just until no streaks of flour remain; be careful not to overmix.
Use a spatula to fold in the chocolate chips, chopped candy bars, and chopped peanuts until they are evenly distributed throughout the thick batter.
Spread the batter evenly into the prepared pan, using the spatula to press it into a smooth, uniform layer.
Bake for 25-30 minutes, or until the top is golden brown and a toothpick inserted into the center comes out with a few moist crumbs attached, but no wet batter.
Allow the blondies to cool completely in the pan set on a wire rack before using the parchment paper to lift them out and cut into squares.