Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan.
In a large mixing bowl, combine the melted butter, brown sugar, and granulated sugar. Mix until well combined.
Add the eggs and vanilla extract to the butter mixture, and beat until smooth.
In a separate bowl, whisk together the all-purpose flour, baking powder, salt, and almond flour. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the sliced almonds and mini chocolate chips, if using.
Pour the batter into the prepared baking pan and spread it evenly.
Bake for 25-30 minutes, or until the edges are golden and a toothpick inserted in the center comes out clean.
Allow the blondies to cool in the pan for at least 15 minutes before cutting into squares.