Preheat oven to 350°F (175°C) and line a 9×13 inch metal baking pan with parchment paper.
In a medium bowl, whisk gluten-free flour, ground almonds, baking powder, salt, and cinnamon to combine.
In a large mixing bowl, cream butter and sugar until light and fluffy (1-2 minutes). Add eggs one at a time, mixing well after each. Stir in vanilla extract.
Gradually add the dry ingredient mixture to the wet ingredients, mixing until a dough forms. Press half the dough into the prepared pan to form the base.
Top the base with a thick layer of jam, spreading it to the edges. Crumble the remaining dough evenly over the jam.
Bake for 25-30 minutes, until the top is golden and the edges are crisp. Let cool completely before slicing into bars.
Dust with powdered sugar before serving.