Prepare the angel food cake according to instructions on the box. When the cake is is baked and cooled, gently cut it in two halves.
Slice the strawberries and put them in a bowl with sugar and the juice of half a lemon. Finely chop the mint and add to the strawberry mixture. Set aside for at least 15 minutes to draw out the juices.
Whip the cream with a stand mixer and gently incorporate the vanilla extract and confectioner's sugar. If you're whipping the cream by hand, start by freezing the whisk and mixing bowl so the cream stays cool as long as possible and is easier to whip.
To prepare the cake, generously spread the whipped cream onto the cut angel food cake, and top with the strawberry mixture, Place the second half of the cake on top, and use the remaining whipped cream and any left over strawberries for the top of the cake!