Preheat the Oven: Preheat your oven to 180°C (356°F).

Prepare the Oat Flour: If you have whole oat flakes, pulse them in a blender or food processor until they resemble a fine flour.

Make the Dough: In a mixing bowl, combine the ground oat flour with water and salt. Mix well to form a smooth dough.

Add Butter: Melt the butter and allow it to cool slightly before incorporating it into the oat mixture. Stir until everything is well combined.

Incorporate Eggs: Crack the eggs into a separate bowl (be sure they're washed first), beat them lightly, and then gradually add them to the dough, mixing continuously to ensure a homogenous blend.

Include Baking Powder: If using baking powder, sprinkle it into the dough and fold it in to help the snack puff up a bit during baking.

Bake: Pour the batter into a greased baking tray or line it with parchment paper for easier cleanup. Spread the mixture evenly.

Bake for 40 Minutes: Bake for 40 minutes or until the top is golden and the edges start to pull away from the sides of the tray. The texture should be crunchy on the outside and slightly tender inside.

Cool and Serve: Let the baked oatmeal cool in the pan for a few minutes before cutting it into bars or squares.