For the Meringue:
Preheat your oven to 250F and line a large baking sheet with parchment paper or a silpat mat.
Add the egg whites to the bowl of a stand mixer fitted with the whisk attachment.
Beat on medium speed until the egg whites become foamy-- about 15 seconds.
With the mixer on medium-low speed, slowly add the sugar (about 1 tablespoon at a time). Adding all of the sugar should take about 2 minutes.
Once all of the sugar has been added, turn the mixer to high speed and beat until the egg whites form a stiff peak.
Add the vanilla and mix to combine-- scrape down the sides of the bowl as needed.
Pipe or spoon the mixture onto the baking sheet. I used a Wilton 1M tip to pipe 3” Meringue.
Bake for 1 hour, then turn the oven off (but leave the meringue inside) and allow it to cool for one hour.
For the Topping
In a small bowl, combine the strawberries, blueberries, sugar, and lemon juice. Set them aside to macerate for 10 minutes.
Using a hand mixer whip cream until stiff peaks.
To Serve:
To serve, fill each meringue with whipped cream and top with macerated berries. Enjoy immediately.