In the bowl of a stand mixer with the whisk attachment, beat the egg whites and granulated sugar on high, until stiff peaks form.

Add the cocoa powder, corn starch, lemon juice and vanilla extract and mix until well blended.

Transfer to your lined sheet. Use a spatula to make 6 round rings. Make sure there is an indent in the center of each circle - the centers will rise during baking.

Bake for 1 hour and 30 minutes. Turn off the oven and allow the meringues to cool in the oven with the door closed for at least 1 hour. When you remove them from the oven, make sure they are completely cool before assembling your pavlova cake.

Beat the whipping cream on high for 3-4 minutes. Slowly add the powdered sugar until the whipped cream is thick and fluffy.

When you are ready to serve, assemble your cake. Place one meringue on a plate. Top that with whipped cream and repeat until you have used 3 of your meringues. Place several strawberry chunks into the whipped cream and on top of the cake. Sprinkle chocolate shavings on top.