• Preheat oven to 350 ℉ and line an 8x8 light colored baking pan with parchment paper and set aside.

For the Brown Butter

• Melt 15 tbsp (210 g) unsalted butter in a medium sauce pan on medium heat. Stir the butter to make sure it melts evenly. Once the butter is completely melted, it will start to foam up. Continue stirring the butter. As it cooks, it will start to change into a deeper color. This could take 6-8 minutes.

  You'll start to notice a nutty aroma and the butter will begin to have brown specs at the bottom of the pan. The entire process of browning butter from start to finish should not take more than 10 minutes on medium heat.
  15 tablespoon (210 g) unsalted butter
• Once butter is browned, divide brown butter into two bowls (making sure you weigh out correct measurements for both elements). Set it aside to cool for about 10-15 minutes.

  If you have a little left over, you can add it to the blondies.

For the Almond Frangipane

• Mix the batter: In a small bowl, add the cooled brown butter and sugar and mix using a spatula. Then add the egg, vanilla extract, salt and almond flour and mix until combined. The mixture will be pretty loose and liquidy, but don't fret. It's ok! Set aside while making the blondies batter.
  4 tablespoon (56 g) browned butter, ⅓ cup (66 g) granulated sugar, 1 large egg, ¼ teaspoon vanilla extract, ¼ teaspoon salt, ⅔ cup (64 g) almond flour, ¼ teaspoon almond extract

For the Blondies

• Mix the batter: In a medium bowl, add cooled brown butter and sugars and mix using a spatula until combined. Add the egg, yolk, and vanilla and mix until combined. Add the salt, almond flour, and all purpose flour and mix until incorporated.
  8 tablespoon (115 g) browned butter, ⅔ cup (133 g) brown sugar, ⅓ cup (66 g) granulated sugar, 1 egg + 1 egg yolk, 2 teaspoon vanilla extract, ½ teaspoon salt, 1¼ cup (150 g) all purpose flour, ¼ cup (24 g) almond flour, 1 teaspoon almond extract
• Bake the Blondies: Pour the batter into the prepared baking pan and spread it out. Then add the almond frangipane layer and spread it on top. Sprinkle the sliced almonds on top of the layer of frangipane. Bake for 30-35 minutes (start checking at 25-28 minutes, especially if your oven runs hot). You'll see the sides get a little light brown and the middle will have puffed up some. The frangipane layer should look cooked and not raw. Don't over bake.
  ¼ cup sliced almonds
• Remove from oven and allow to cool. Sift powdered sugar on top, slice, and enjoy.
  Powdered sugar for topping