Preheat your oven to 325°F (163°C) and line several large baking sheets with silicone liners or parchment paper.

In a large bowl, beat the softened butter with the erythritol-based sweetener until light and fluffy, about 2 minutes.

Add in the eggs and vanilla extract, and continue to beat until well combined.

Mix in the almond flour, coconut flour, baking powder, and salt. Beat until the dough comes together.

Fill the canister of a cookie press with the prepared dough, and fit it with your chosen plate.

Press the cookies out onto the prepared baking sheets, making sure to keep the parchment paper secure against the cookie to help release it later.

Bake the cookies for 12 to 14 minutes, switching the pan positions halfway through. They should be set but not overly browned at the edges.

As soon as you remove them from the oven, gently press any decorations into the center of the cookies.

Let them cool completely on the pans.

If you choose to make the chocolate dip, place a bowl over a pan of barely simmering water.

Add the chopped sugar-free dark chocolate and cocoa butter (or coconut oil), stirring until melted and smooth.

Dip each cookie face up into the melted chocolate so only the bottom is coated. Remove them with a fork, letting the excess chocolate drip off before placing them on a waxed paper-lined tray to set.