Prepare the angel food cake mix according to the directions on the box.

Remove the stems from the strawberries, and place the strawberries in a pan lined with parchment paper. Sprinkle the granulated sugar over. Let the strawberries roast for 15-20 minutes (along with the cake), until they are soft and juicy. They should be easy to crush with a fork, and juice should be accumulating in the bottom of the pan.

Place the strawberries and all excess juice in a blender and puree. (This will smell delicious). Then use a fine mesh strainer to strain the strawberries seeds out. Keep the juice and toss the seeds.

Stir the lemon juice into the strawberry juice, and place in the fridge to let chill. This step is important because adding warm strawberry juice to the whipped cream frosting will melt it.

Once the cake is done baking, remove it from the oven and let it cool. You want the cake to cool completely before frosting it.

Prepare the frosting by pouring the whipping cream into the bowl of an electric mixer. Add the vanilla and powdered sugar, and beat on a medium speed until soft peaks begin to form. Then add the strawberry juice, and beat until the cream forms peaks stiff enough to stay put. If the frosting is too soft it will fall of the cake, but if it is overly beaten it will be buttery. So just keep your eye on things, you will know when the frosting is stiff enough. Then go ahead and frost your cake, and keep it chilled until you are ready to serve it.