There's something so satisfying about this elegant and naturally gluten-free dessert; it's crunchy, creamy and sweet. We opted for confectioners' sugar in the meringue, making the pavlova extra crisp on the outside and marshmallow-like on the inside. Crowned with a halo of whipped cream and fresh berries, this dessert is truly heaven-sent! Make the components in advance and assemble the pavlova just before serving.
Position a rack in the lower third of the oven and preheat to 225 degrees F. Line a baking sheet with parchment paper. Draw a 9-inch circle on the paper, then flip it over so the drawing is on the underside.
For the meringue, combine the egg whites, cream of tartar and salt in the very clean bowl of a stand mixer fitted with the whisk attachment. Whisk on medium speed until foamy, about 1 minute. Increase the speed to medium-high and beat until thick and opaque, about 1 minute more. Gradually add the confectioners' sugar, 1/4 cup at a time, and beat until stiff shiny peaks form, about 5 minutes more.
Spread the meringue on the prepared baking sheet, making sure to stay within the drawn 9-inch circle. Create some shallow dips and swoops (this will hold the whipped cream and berries). Bake until the meringue is dry and crisp on the outside, about 2 hours. Turn off the heat and let the pavlova sit in the warm oven to dry out more, about 1 hour. Transfer to a wire rack to cool completely. (The meringue can be made up to several hours in advance.)
Meanwhile, make the whipped cream by whisking together the heavy cream and vanilla in a large bowl with an electric mixer until stiff peaks form, about 3 minutes. Cover and refrigerate until ready to serve.
Toss the berries and raspberry jam in a medium bowl until evenly coated and glossy. Cover and refrigerate for at least 15 minutes and up to 1 hour.
To serve, dollop the whipped cream on top of the meringue and spread into an even layer. Pile the macerated berries on top (drizzle any berry juice on top as well). Slice into wedges and serve immediately.
Make sure your eggs are at room temperature; this will ensure that the right volume is achieved when whipping the whites.