In a food processor, combine cereal crumbs, softened cream cheese, sweetener and cinnamon and pulse until mixture resembles wet sand.
Line an 8×8 baking pan with parchment paper. Press crumbs into the baking dish and bake for 10-15 minutes.
Make the filling
In a bowl, combine the sweetener with the cornstarch and mix well with a fork. Add eggs and beat the mixture until it is completely combined.
Add orange and lemon juices + orange zest and whisk until combined. Mixture will be thin.
Pour the mixture over the crust (tip: you don’t even have to take the crust out of the oven, just pull out the rack and pour the mixture right on top) and bake for 25-30 minutes or until completely set.
Cool thoroughly on a cooling rack (about an hour) before refrigerating for three hours. When ready to serve, lift the entire sheet out by the parchment paper and cut into squares of desired size.