Preheat the oven to 350°F (180°C) and line a cupcake pan with paper liners (possibly green).

In a small bowl, whisk together sifted flours, baking powder, and salt.

In a medium bowl, using an electric mixer, mix together creamy sunbutter, softened butter, sweetener, and baking soda.

Beat in the egg. Add vanilla and heavy cream (or almond milk) and whisk thoroughly.

Using a rubber spatula, stir in the flour mixture until just combined.

Spoon the batter into 12 paper liners. Bake immediately for 20 minutes or until a toothpick inserted into the center comes out clean.

Remove the cupcakes from the pan and let them cool down on a cooling rack.

Beat together softened butter, cream cheese, powdered sweetener, matcha powder, and vanilla. It's best to sift matcha through a fine sieve.

Pipe the frosting on the cooled cupcakes. Decorate with more matcha powder.