Melt butter in a small (microwave safe!) bowl until just melted, but not piping hot. Allow it to come to room temperature while you gather the rest of your ingredients.
Add the almond flour, sweetener, xanthan gum, baking powder and salt to a medium bowl and whisk thoroughly. Pour in the butter and mix until evenly distributed (I just use my hands!). Add in your egg and continue to knead until it forms into a ball. Cover in cling film and place in the freezer for 5-10 minutes to solidify the butter.
Divide the dough into 10 pieces and either roll them out between two sheets of parchment paper or use a tortilla press (see pictures in post). I prefer to use a press as its quicker and gets you a more even thickness (= more even baking!). Either way, just make sure to get it nice and thin as it will puff up a bit when baked.
Sprinkle with a bit more golden erythritol on top and bake for 8-12 minutes or until lightly golden (will depend on size and thickness). And to make them extra crisp, feel free to do a double bake biscotti-style (i.e. let them cool, and bake them again for 5 minutes). Or use your dehydrator if you've got one. (And do remember that sugar alcohols can take a little longer to crisp up than sugar, even a couple hours!).
Store in an airtight container for 5 days, and the dough keeps well in the fridge for 3 days or up to 3 months frozen.
You’ve got one option if keto: erythritol, that’s it! You see, it’s the only sweetener that lends a very similar crunchandchew to sugar for crisp baked goodies (i.e. cookies). And no other low carb natural sweetener does that; allulose and xylitol will give you soft cereal, you’ve been warned ;).