Make the cream cheese whipped cream according to instructions and keep it refrigerated until needed.
Make and cool the cake according to instructions then cut it into 1/2”-1” cubes. Toss the strawberries in the jam.
In 8 oz mason jars, put 2-3 tablespoons of cubed cake at the bottom. Spoon a portion of strawberries equal to the cake over the cake then a tablespoon or two of the cream. Repeat the layers once, then finish with strawberry slices. Serve immediately.