Combine 1 tbsp flax seeds with 3 tbsp water and set aside to make a "flax egg." Let sit for about 10 minutes while you prepare the rest of the batter.
Mix oat flour, baking powder, and salt.
If you don't have oat flour... combine 1 1/2 cups rolled oats in a blender with the baking powder and salt. Blend until broken down into a flour.
Combine softened butter, yogurt, sugar, honey, "flax egg," vanilla extract, and milk. Mix until smooth.
Add oat flour mixture and stir until evenly combined.
Preheat oven to 350 degrees Fahrenheit.
Meanwhile, chill batter for 10 minutes in the refrigerator. Scoop 1/2 tbsp sized dollops of dough onto a prepared baking pan.
Cook for 15-18 minutes, let cool, and enjoy!
Store in an airtight container in the refrigerator for 3-5 days, or in the freezer for months.
Serving Size 1 cookie