Begin by preparing the double strawberry sauce, which will be served alongside each slice. Puree 1 1/4 cups of the sliced strawberries with the 1/2 cup strawberry jam, then refrigerate until you're ready to serve.
Next, prepare the cheese filling by beating together the 8 ounces of softened cream cheese or mascarpone, 1/3 cup confectioners' sugar, and 1 tablespoon of the Grand Marnier or orange juice until the mixture is well blended and smooth.
In a separate bowl, beat the 2 cups of heavy whipping cream with the remaining 2 tablespoons confectioners' sugar and 2 tablespoons liqueur until soft peaks form. Gently fold 1/2 cup of this whipped cream into the cheese mixture to create a lighter, fluffier filling.
With a serrated knife, carefully cut the angel food cake into three horizontal layers. Drizzle each layer with 1 tablespoon of the remaining liqueur to add moisture and flavor. Begin assembly by spreading the bottom cake layer with one-third of the cheese filling, then cover it with one-third of the remaining sliced strawberries.
Place the middle cake layer on top, spread it with half of the remaining filling and sliced strawberries, then add the final cake layer. Top with the remaining cheese filling and sliced strawberries, then frost the entire exterior of the cake with the remaining whipped cream.
Refrigerate the completed cake for at least 2 hours, or up to 24 hours before serving to allow the flavors to meld and the structure to set. When ready to serve, use a serrated knife to cut clean slices and plate each piece with a generous portion of the double strawberry sauce on the side.