Combine the diced strawberries and strawberry jam.
Stir gelatin into cold water.
In a small bowl, combine softened cream cheese, powdered sugar, and lemon zest.
In a large bowl, pour the room-temperature whipped cream, add the prepared gelatin, and mix. Pour the condensed milk and vanilla extract into the mixture, blend the ingredients, and then add the cheese mixture.
Slowly pour in the lemon juice and mix well.
Spread about 1/4 of the filling onto the bottom of the prepared pan. Pour half of the strawberry mixture over the filling. Top with a single layer of sponge cake.
Then repeat: Spread half of the filling mixture over the cake pieces, spread the remaining strawberry mixture on top, top with the sponge cake pieces, and finish with the remaining 1/4 of the filling.
Refrigerate for four hours or overnight.
Before serving, invert the cake onto a serving plate, remove the plastic wrap, cover with strawberry frosting, and garnish with fresh strawberries.
