Reserve 4 strawberries for garnish.
Remove stems and cut remaining strawberries up and put in medium bowl.
Sprinkle with sugar and allow to sit for at least 30 minutes.
Cut cake into 1" cubes.
Combine heavy cream, powdered sugar and vanilla. Whip until stiff peaks form.
Transfer to zippered bag and place in freezer for 15 minutes.
Clip corner of bag to allow for piping.
In each jar layer cake, then strawberries, then whip cream and then repeat these layers.
Take reserved strawberries and use for garnish on each jar.