Preheat the oven to 350 F (175 C).

Grind 1/2 cup rolled oats in a mini blender and add to a large mixing bowl with remaining oats, ground flaxseeds, cinnamon, and a pinch of salt. If using the optional ground cloves or cardamom, be sure to add that as well.  Combine these dry ingredients with a whisk or large spoon.

Add remaining ingredients and stir until well combined.

Carefully spoon the muffin mixture into a silicone (nonstick) muffin tin or 8x8 or 9x9 square parchment-lined baking pan. 

Bake at 350 F (175 C) for 35 to 40 minutes.

This recipe makes 12 standard-size muffins or 4 servings of 3 muffins. After these apple cinnamon oat muffins have cooled to room temperature, you can store leftovers in a covered container in the refrigerator for up to 4 days or in the freezer for up to 4 months. To reheat from frozen, microwave uncovered at reduced power for 90 seconds. If still cold, microwave at full power for 30 seconds.