Preheat oven to 350.
Combine the first four ingredients into a food processor and pulse for 40 seconds or until the crust mixture comes into a ball and holds together.
Line an 8x8 glass baking dish with parchment paper. Press crust mixture into the pan and using a skewer or poke fork holes over the crust.
Bake for 15 minutes or until the crust is light brown. Remove from oven and let cool.
Using a juicer, squeeze out 2/3 cup of juice from the lemons (limes or oranges - whatever you're using). Using the lemon peel, zest 2 Tablespoons from the lemon peel.
Now in a large bowl, combine the lemon juice, eggs, erythritol, lemon zest and 1/4 cup of oat flour and combine well. Pour over crust.
Put into oven for about 30 minutes. Bake the lemon bars until the filling is perfectly set and jiggles slightly in the center.
Cool complete at room temperature for about 1.5 hours and then refrigerate for 1.5 hours or more.
When ready to serve, using a sieve dust the Swerve Powdered Sugar over the top and then slice into 6 HUGE bars. If they don't disappear immediately, refrigerate in a covered container.
If you follow Weight Watchers (WW) each HUGE bar is only 5 WW Points!!!!!