To make the meringues, preheat your oven to 225F. In a mixer or using a hand blender, whip the egg whites until frothy and slowly start adding the sugar one tablespoon at a time. Add vanilla and keep whipping until meringue is stiff and shiny. Spoon onto a baking sheet lined with parchment and bake for 1.5 hours. Turn oven off and let meringues sit overnight.
To assemble Eton Mess: layer whipped cream, fresh berries, and crumbled meringue. Serve immediately.
Notes
If you can't find vanilla powder, substitute for either vanilla extract or the inside of a real vanilla bean. You can use any kind of extract you'd like!