Combine blueberries, walnuts, coconut sugar and lemon zest. Spread over the base of a springform pan.
Combine the cake mix and all other ingredients. Pour over the blueberry base.
Dollop with half the lemon curd. Sprinkle the top with an even layer of coconut sugar.
Bake at 325F for 45-60 minutes. Let cool completely before inverting and dolloping the blueberries with the remaining lemon curd.
