Preheat oven to 350°F.
Line a baking sheet with parchment paper.
In a large bowl, combine the oat flour, flour, baking powder, and salt.
Make a well in the dry ingredients, then pour in melted butter and water. Mix until it forms a ball of dough. If dough appears dry and crumbly, add a bit of water 1 tsp. at a time until you have a ball of dough that doesn’t fall apart.
Cover the bowl and let the dough rest for 10 minutes.
Turn the dough onto a floured surface and roll out to desired thickness, between ⅛ to ¼-inches.
For round bannocks: using a 3-inch round cookie cutter or a glass to cut out circles.
For rectangular bannocks: Roll out the dough to an 8- x 10-inch rectangle (cut into 16 pieces), or an 8- x 9-inch rectangle (cut into 12 pieces).
Place the cut dough pieces on the prepared baking sheet. Bake for 20-23 minutes.
Remove to wire rack to cool. Enjoy with butter, jam, or both!