Preheat oven to 350°F (175°C).
In a bowl, combine almond flour, coconut flour, almond milk, melted coconut oil, egg, vanilla extract, and sugar substitute. Mix until a dough forms.
Divide the dough into two equal parts. Roll out each part between two sheets of parchment paper into a rectangular shape.
Cut the rectangles into smaller, equal-sized rectangles. These will be the top and bottom of your Pop Tarts.
Spoon a small amount of sugar-free jam onto half of the bottom rectangles, leaving space around the edges.
Place the matching top rectangles over the jam-covered ones, pressing the edges to seal. You can use a fork to crimp the edges.
Transfer the assembled Pop Tarts onto a baking sheet lined with parchment paper.
Bake for 12-15 minutes or until the edges are golden brown.
Optional Icing: Mix powdered sweetener with a bit of almond milk and something to add color and flavour like strawberry jam, cacao powder or cinnamon
Allow the Pop Tarts to cool before icing them. Drizzle the low-carb icing over the top.