Pre-heat oven to 350°F. Spray 8x8 cake pan with cooking spray.
Weigh or lightly spoon flour into a dry measuring cup. Level with a knife. Combine flour, potato starch, salt, and baking powder. Stir with a whisk.
In another mixing bowl, combine the Splenda Sugar Blend and Coconut Oil, beating with a mixer at medium speed until blended. Mixture will be like damp sand.
Add egg and egg white, one at a time, beating well after each addition, then stir in coconut extract to almond milk.
Add flour mixture and milk/extract mixture alternately to egg mixture, beginning and ending with flour mixture.
Pour batter into cake pan and bake in 350 degree oven for 18-23 minutes or until cake springs back when touched lightly in the center. Cool.
Once cake has cooled, poke holes in cake using the handle of a wooden spoon. I poked the holes about 1 inch apart all around the cake.
Make pudding mix per the package directions. When thickened but still pourable, pour the pudding mix over top of the cake, spreading it out to fill up the holes. Let sit in refrigerator at least 2 hours before serving.
Prior to serving, remove cake from refrigerator and spread with cool whip. Cut into 16 pieces and serve.
Notes
Make sure you don't use unsweetened almond milk in place of the milk for the pistachio pudding mix. If you do, the pudding will not set.