Preheat oven to 350 degrees. Line baking sheets with parchment. Cream together erythritol and butter. Slowly add in eggs, vanilla, unflavored gelatin, and baking powder. Mix in coconut flour and almond flour. In a separate bowl, combine 1/4 cup erythritol and cinnamon. Use a medium cookie scoop to shape cookies into balls and roll in cinnamon and sweetener mixture. Place cookie dough balls on prepared cookie sheet, a couple inches apart. If you prefer thin and crunchier cookies, flatten the cookie dough balls prior to baking. Bake in preheated oven for 10-15 minutes. Remember, baked goods made with erythritol are much softer when they are hot and will crisp up as they cool.
Preheat oven to 350 degrees, and line a 9×13 baking dish with parchment. Cream butter and erythritol until smooth, and slowly mix in coconut flour. Add in eggs, baking powder, and vanilla, mixing until combined. Press dough into the base of the pan and bake for 15-20 mins or until edges of lightly golden. Let cool completely.
In a small bowl, soak gelatin in 1 tbsp of water. Combine eggs, lemon extract, lemon juice, and erythritol and heat in double boiler. Stiring constantly, bring mixture to 170 degrees. Remove from heat and whisk in prepared gelatin. Let mixture cool to 120 degrees before transfering to a food processor. Add butter and blend until smooth. Pour over cookie crust and let chill for 2-3 hours or until set. Cut into 40 squares.