Creating Key Lime Pie Bars – Browned Butter Blondie is straightforward. Follow these steps to achieve the perfect bars:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Grease an 8×8-inch baking dish.

2. Brown the Butter: In a medium saucepan over medium heat, melt the butter until it begins to brown and smells nutty. Remove from heat and let cool slightly.

3. Mix the Blondie Batter: In a large bowl, combine browned butter and brown sugar. Stir until smooth. Add eggs and vanilla extract, mixing well.

4. Combine Dry Ingredients: In another bowl, whisk together the flour, baking powder, and salt. Gradually add to the wet mixture, blending until just combined.

5. Spread the Base: Pour the blondie batter into the prepared baking dish, smoothing it out evenly. Bake for 25-30 minutes until a toothpick inserted in the center comes out clean. Let cool while preparing the key lime layer.

6. Prepare the Key Lime Curd: In a separate bowl, whisk together the key lime juice, granulated sugar, egg yolks, sweetened condensed milk, and the lime zest. Pour this mixture over the cooled blondie base.

7. Bake Again: Return the dish to the oven for an additional 10-15 minutes until the curd is set but still slightly jiggly. Allow it to cool completely at room temperature before transferring to the refrigerator to chill for at least 30 minutes.