Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the almond flour, granulated erythritol, salt, and baking powder. Whisk thoroughly.
In another bowl, cream the softened butter until light and fluffy. Add the egg, vanilla extract, and almond extract (if using). Mix until smooth.
Gradually add the dry ingredients to the wet mixture. Stir gently until a dough forms.
Pour the dough into the prepared baking pan and spread evenly.
Bake for 20-25 minutes until edges are lightly golden and a toothpick comes out clean.
Let the bars cool in the pan for 10 minutes, then lift out and cool completely on a wire rack before cutting into squares.