Preheat oven to 350F.
Line a 8" by 4" loaf pan with parchment paper.
In a medium glass bowl, whisk together melted butter, sugar, salt, vanilla, egg and matcha.
Add in the almond flour, all-purpose flour, and baking powder. Fold until combined.
Transfer the mixture to the prepared loaf pan.
Bake at 350F for 35 minutes, or until a toothpick inserted comes out clean, or with the slightest bit of crumbs clinging to it.
Remove from oven, let cool in pan for 5 minutes, and transfer to a cooling rack. Cut into 8 squares and dust with additional matcha prior to serving.
Store in an airtight container for 1 week at room temperature.