100g butter, 60g almond flour, 1 egg, stevia (about 60g), 4-5 drops vanilla extract
Preheat the oven to 170°C (338°F).
Put the butter and sweetener in a large bowl and mix until smooth.
Add the egg and mix well until combined.
Sift in the flour, matcha powder, and salt, then gently fold together.
Spread the dough evenly into a square pan lined with parchment paper.
Bake in the oven at 180°C (356°F) for 20-25 minutes.
Let it cool completely before cutting into appropriate sizes.