Begin by preheating the oven to 180 C (350 F) and line a baking tray with parchment paper. I also like to draw a 22(9 inch) circle on the parchment, which acts as a guide when shaping the meringue.
Next, if you haven't already, separate the egg yolks from the whites. I like to do this using two bowls, one for the yolks and one for the whites. Crack the egg, then move the yolk back and forth between the shell to release the whites. Make sure there are no traces of the yolk in the whites, as that may affect how well the whites whip.
Transfer the egg whites to a large, clean glass bowl, and whip them using an electric beater till you’re left with a thick, foamy mass. The eggs should be stiff, so if you turn the bowl over, the shouldn't move or fall out.
Gradually trickle in the sugar, one or two tablespoons at a time, beating well after each addition, it will take around 10 minutes in total. The mixture will be glossy, stiff and smooth. If you rub it between your fingers, you shouldn’t feel any sugar granules.
At that stage, add in the cornstarch and vinegar (which help stabilise the whites and prevent them from deflating), as well as the espresso powder and salt.
Scrape down the sides of the bowl while whipping to make sure everything is well-incorporated.
Scoop the mixture and spoon onto the prepared parchment tray, forming it into a 22 cm (9 inch circle). Use an offset spatula or knife to spread the mixture out, and make sure to flatten the top. I also like to use the back of a spoon, dragging it up vertically around the mass to create an indented pattern (see video).
Reduce the oven temperature to 150 C (300 F) and place the pavlova on the middle rack of the oven. I also like to add an empty tray on the top rack, as I find that it helps even the baking. Bake the pavlova for one hour, or until it has puffed slightly.
Turn off the oven, and let the pavlova cool completely with the oven door left slightly ajar. It will likely take around two hours to cool completely. In the meantime, prepare the coffee cream.