Prep. Pre-Heat Oven to 350 °F. Spray Pie Plate / Tin with cooking spray. Place pie tin on a sheet pan and place near the oven.
Blend. Layer dry ingredients into blender and then add in the wet ingredients. Cover the blender and blend for 1-2 minutes until you have a nice smooth batter.
Bake. Bring the blender to your pie tin near the oven and pour in the batter in the greased pie tin. Using the sheet pan, transfer carefully into the oven and bake for 1 hour.
Rest. Take the Calamansi Pie out of the oven and leave to rest on the counter for 2 hours.
Serve. Cut into slices and serve with vanilla or coconut ice cream.