01 -
Preheat the oven to 120°C (250°F). Line two baking sheets with parchment paper and set aside.
02 -
Using an electric mixer, whip the egg whites on medium speed for 1 minute. Gradually add the granulated sugar while continuing to mix.
03 -
Once all sugar is incorporated, increase speed to high and whip for 9 minutes (total whipping time 10-12 minutes). The meringue should form stiff, glossy peaks. Add purple food coloring around minute 8 of whipping if making solid-colored pavlovas.
04 -
Gently fold in the cornstarch and lemon juice with a spatula until fully incorporated.
05 -
For color swirls, place a piping bag in a cup with sides folded over for support. Using a small brush, paint vertical lines of gel food coloring from the tip to the top of the inside of the piping bag.
06 -
Transfer meringue to piping bags fitted with an open star tip. Pipe 9 cm (3 1/2 inch) nests onto the prepared baking sheets, creating a shallow depression in the center for filling later.
07 -
Bake in preheated oven for 1 hour, then turn off the oven and leave pavlovas inside for an additional 30 minutes without opening the door. This prevents cracking from sudden temperature changes.
08 -
Allow pavlovas to cool completely before removing from the oven and filling.
09 -
In a small saucepan, combine blackberries, sugar, lemon juice, and 2 tablespoons of water. Bring to a boil over medium heat and cook for 5-10 minutes, stirring occasionally. Add more water or lemon juice if mixture becomes too dry.
10 -
In a small bowl, dissolve 1 tablespoon cornstarch in 2 tablespoons water. Add to the simmering blackberry mixture and cook for 1 minute until thickened. Transfer to a bowl and refrigerate until completely chilled.
11 -
Just before serving, whip the cold heavy cream with powdered sugar and vanilla using an electric mixer on medium-high speed for about 3 minutes until stiff peaks form. Transfer to a piping bag fitted with a decorative tip.
12 -
Spoon blackberry jam into the center depression of each pavlova. Pipe whipped cream on top and garnish with fresh blackberries.