Prepare the vanilla cake mix according to the package directions, substituting water with vanilla almondmilk and folding in orange zest. Pour into a greased 9 x 13 inch baking pan and bake at 350°F for 25-30 minutes.
Allow the cake to cool in the pan for 10 minutes, then invert onto a wire rack to cool completely.
Poke holes all over the top of the cooled cake with a skewer, spacing about an inch apart.
Dissolve orange JELLO in boiling water, then mix in fresh squeezed orange juice. Pour over the poked cake and refrigerate for at least 3 hours.
Combine canned mandarin oranges with syrup and vanilla instant pudding mix in a bowl, stirring well.
Fold in Cool Whip gently into the mandarin orange mixture until smooth.
Spread the orange-vanilla frosting over the cooled, JELLO-soaked cake.
Refrigerate the frosted cake for at least 30 minutes before serving.