Mix together ground oats, brown rice flour, tapioca starch, baking powder, baking soda, pumpkin pie spice, cinnamon and salt in a medium bowl. In a large bowl, mix together yogurt, milk, lemon juice, lemon zest, eggs, vanilla, pumpkin puree, maple syrup and olive oil. Add dry ingredients to wet ingredients and mix until blended. Stir in chocolate chips. Let sit for 15-20 minutes so flours absorb liquid ingredients.