Preheat oven to 350 degrees.

Add the oats to a blender and pulse until oats are ground into a fine powder.

Add sugar, baking powder, baking soda, salt and almond flour to the ground up oats and blend a few seconds so all the dry ingredients are well incorporated.

Add the coconut oil to a bowl and microwave it for 10 seconds or until it's melted but not hot. Add it to the dry ingredients in the blender.

Also add in the egg and milk and blend well. 

Then, add in the lemon juice and lemon and blend a few seconds until everything is well incorporated.

Line a 6 muffin tray with muffin cups and spoon Lemon Muffin mixture into these cups and bake 18-20 minutes. Then, remove from the oven and let cool a bit before glazing. *If you glaze while warm, that glaze will run everywhere.

Add the granulated sugar and arrowroot powder (or can use cornstarch) to a blender and blend on high speed for about 20 seconds.

When done, let mixture sit for about a minute before opening. *If you open it too quickly, your immediate surroundings will be covered with a fine layer of powdered sugar 

Add powdered sugar to a bowl and mix in the lemon juice and lemon zest. Drizzle glaze over Lemon Muffins, (optional) sprinkle on some slivered almonds and enjoy.