Prepare pavlova the day before your gathering. Preheat oven to 250F. Trace two inch 9-inch circles onto 2 sheets of baking paper. Place on 2 baking sheets, trace-side down.
In a mixer bowl, beat egg whites using an electric stand mixer set on medium speed, until soft peaks form. Sprinkle cream of tartar, then gradually add in sugar, 1 tablespoon at a time, beating well after each addition. Beat until mixture is thick and has a glossy peaks, about 7 to 10 minutes. Sift cornstarch and cocoa powder together. Add to egg-whites and quickly beat on medium high for a few seconds until well incorporated. Spoon meringue onto traced circles on prepared trays. Spread to cover the entire circle. Swirl with a spoon to leave some pointed ends.
Place trays in the oven and bake for 1 ½ hours until surface is dry and crisp. Turn off oven and leave pavlova inside with the oven door left slightly open for at least six hours overnight. Store pavlova in an airtight container at room temperature. Do not refrigerate to avoid making it soggy.
To make the chocolate ganache, simmer cream in a sauce pot over low heat. Whisk in cocoa powder. Pour hot cream over your bowl of chocolate chips. Cover for minutes to soften the chocolate. Uncover and gently mix until smooth. Cover surface with plastic wrap to avoid developing a skin. Cool to room temperature then chill to spreading consistency.
To make the whipped cream, place cold whipping cream in a mixing bowl that has been chilled for 15 minutes. Add confectioners’ sugar and whip until thick and double in volume.
To assemble, place one pavlova on a serving plate. Spread 2/3 of chocolate ganache over pavlova. Spread half of whipped cream over ganache. Place 2nd pavlova on top. Spread remaining chocolate ganache around the edge of the pavlova. Spoon remaining whipped cream in mounds over the ganache. Arrange fruits on top of cream, forming a wreath-like decor. Serve right away.