In a clean and completely dry blender, pulverize ¼-cup oats into a flour, then transfer to a small bowl and set aside.
Pulse another ¼-cup oats a few times to chew up and look like instant oats. Set aside.
In a mixing bowl, combine cooked lentils, ketchup, mustard, soy sauce, and spices together.
Add 2 tbsp of the oat flour and nutritional yeast, stirring to combine.
Add the “instant” oats and remaining ½-cup rolled oats, stirring to mix.
Taste, adding another 1 tbsp soy sauce or cayenne if desired.
If the mixture is really wet and loose, add another 1-2 tbsp oat flour.
Chill mixture for 30 minutes if possible.
Preheat to 450F. Line cookie sheet with parchment paper.
With clean but wet hands, pick off and shape 10 balls.
Place on baking sheet and bake 10-12 minutes, or until the balls are firm on the outside (not still mushy when you touch them,but they don’t need to be super firm either because the firm as they cool a little).
Remove from oven and let cool to room temperature, about 15 minutes.