To Prepare Meringues
Preheat oven to 275° F. Line a large, rimmed baking sheet with parchment paper.
Place the egg whites in a large bowl. Using an electric mixer on low speed, beat the egg whites until frothy, about 1 minute. Increase the speed to medium-high and continue beating until soft peaks form, 2 to 3 minutes. Then, add the sugar, 1 tablespoon at a time, and beat until stiff, shiny peaks form, about 5 minutes. Add the vinegar, almond extract and salt and beat for 1 minute.
Using a spoon, transfer the meringue batter to the lined baking sheet, forming 3-inch rounds about 2 inches high and, with the spoon, making several peaks on each round. You should have 10 meringues. If you like, use the back of the spoon to make a slight depression in each meringue, to act as a cup to hold the berries.
Bake the meringues until very faint color appears on the peaks, about 1 hour. The outside will be crisp and the inside soft. When they are done, turn off the oven, crack the oven door open, and let the meringues dry out in the oven as it cools, at least 1 hour or up to 6 hours to ensure they are fully dry.
To Prepare Sweetened Whipped Cream (optional)
Pour the cream into a large bowl. Using the electric mixer on medium-high speed, beat until soft peaks form, 3 to 4 minutes. Add the sugar and almond or vanilla extract and continue to beat until stiff peaks form, 2 to 3 minutes longer.
Place each meringue on a dessert plate. Top the meringues with the berries and then with a scoop of the whipped cream, if using.
Adapted from the Davis Farmers Market Cookbook by Georgeanne Brennan and Ann M. Evans