Preheat your oven to 350°F (175°C). This step is crucial to ensure your bars bake evenly.
Grease the baking pan with the 1 tablespoon of butter. If desired, line the pan with parchment paper for easier removal later.
In a large mixing bowl, whisk together the 2 3/4 cups of flour, 2 cups of sugar, 2 teaspoons of baking powder, 1 1/2 teaspoons of baking soda, and 1 teaspoon of kosher salt until well combined.
In another bowl, beat the 3 large eggs until frothy. Add the 3/4 cup of melted butter and 1/2 teaspoon of vanilla extract, mixing until smooth.
Pour the wet mixture into the dry ingredients and stir until just combined. Be careful not to overmix, as this can lead to dense bars. Fold in the 1 cup of chopped pecans gently.
Pour the batter into the prepared baking pan, spreading it evenly. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
While the bars are baking, prepare the frosting. In a mixing bowl, beat the 8 ounces of softened cream cheese until creamy. Gradually add the 3 1/2 cups of confectioners' sugar, mixing until smooth and fluffy.
Once the bars are baked and cooled, spread the cream cheese frosting evenly over the top. Allow the frosting to set for a bit.
Cut the bars into squares, serve them on a platter, and watch as they disappear!
