Preheat oven to 350˚ F and spray 3-8-inch cake pans with cooking spray then line with parchment paper; set aside.
In a large bowl, whisk together the flour, freeze-dried berries, baking powder, salt and baking soda; set aside.
In a mixing bowl, cream together the oil and sugar on medium speed for 3 minutes.
Add the eggs, one at a time, blending each until well incorporated.
Add the milk, lemon juice and lemon zest and mix on low until a smooth batter is formed.
Divided the batter evenly into the three prepared pans and bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Cool in pans for 10 minutes then invert onto a wire rack and remove the parchment paper. Allow to cool completely.
Filling
In a medium saucepan, combine all the ingredients and cook over med-low heat, stirring frequently, until the berries have broken down and the mixture is thick.
Pour into a container and refrigerate until cool.
Frosting
In a mixing bowl, cream together the shortening and zest until smooth. Add the lemon juice and salt and mix on low to start blending.
Add the powdered sugar, a little at time, mixing to blend.
Add the milk a tablespoon at a time along with the powdered sugar until you have reached your desired consistency. Store covered until ready to use.
Assembly
Level each cake by using a serrated knife to slice off any domed tops.
Place the first cake, bottom side up, on a serving platter.
Pipe a frosting border around the outer edge of the cake. Dollop half the filling into the center and spread out evenly.
Top that layer with the second cake, right side up, and repeat the frosting and filling steps.
Place the final cake on top, bottom side up and frost the entire cake with the remaining frosting.