Creating Key Lime Pie Bars – Browned Butter Blondie is easy! Follow these simple steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Grease and line a 9×13-inch baking dish with parchment paper, leaving an overhang for easy removal.

2. Brown the Butter: In a saucepan, melt the unsalted butter over medium heat, stirring continuously until it turns golden brown and fragrant. This should take about 5-7 minutes. Be careful not to burn it!

3. Make the Blondie Batter: In a mixing bowl, combine the browned butter and brown sugar. Whisk until smooth. Next, add the eggs, one at a time, and mix in the vanilla extract until well incorporated.

4. Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, and salt.

5. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, stirring until just combined.

6. Spread the Blondie Base: Pour the blondie batter into the prepared baking dish. Smooth it out evenly using a spatula.

7. Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes. The edges should start to pull away from the sides, and a toothpick inserted in the center should come out mostly clean.

8. Prepare the Key Lime Filling: While the blondie base bakes, prepare the filling. In a mixing bowl, whisk together the sweetened condensed milk, key lime juice, egg yolks, lime zest, and a pinch of salt until fully combined.

9. Pour the Filling: Once the blondie base is baked, remove it from the oven. Pour the key lime filling over the hot blondie crust, spreading it evenly across the top.

10. Return to Oven: Bake for an additional 10-15 minutes until the filling is set but still slightly wobbly in the center.

11. Cool Down: Allow the bars to cool at room temperature. Once cooled, refrigerate for at least 2 hours to allow the filling to set completely.

12. Slice and Serve: Once fully chilled, use the parchment overhang to lift the bars from the pan. Cut into squares or rectangles for serving.