Puree the blueberries into as smooth as possible. I had 3/4 cup blueberry puree, from a bit more than a cup of Blueberries.

Add Oat flour, sugar, salt, spice and whisk well for a minute.

Pour the mixture over parchment lined baking sheet and spread into a thin layer using a spatula. A bit thicker on the sides to avoid burning.

Bake at 325 degrees F for 45 minutes to an hour until just about crisp.(It will continue to crisp up while cooling).

Turn around twice in between for even baking.

Use pizza cutter when still warm to make cuts.

The central part might feel like fruit leather if the batter layer was thick. With a thin and even spread, they come out crisp.

Cool completely, break into pieces and store in an airtight container.