Place a mixing bowl and beaters/mixer into the freezer so they will be icy cold for the whipped frosting.
Bake cake according to box instructions in a 9X13 pan.
Let cool completely then flip upside down onto a tray or baking sheet.
Using a large serrated knife, slice through the middle of the cake width wise and separate the layers.
Spread the strawberry cream cheese spread onto the bottom of the split layer and smooth onto the whole layer.
Replace the layer so the strawberry spread is in the middle of the cake.
Take the bowl and beaters out of the freezer and add cream cheese and sugar to the bowl.
Mix on medium until smooth then slowly add the heavy cream. Beat on high until fluffy.
Add vanilla and almond extract and beat on low until blended.
Frost onto cake (you will have some left over) covering the top and sides.
To decorate: in the top left corner add 6-7 rows of blueberries about 6 across, these are the stars of the flag.
Now add horizontal rows of sliced strawberries, lying flat on their sides slightly on top of one another. You should have about 4 rows.
Chill until ready to serve then slice into squares and enjoy!