Using a stand mixer fitted with the whisk attachment (or a handheld electric mixer), whisk 8 egg whites on medium-high speed until foamy.
Add the cream of tartar and continue whisking until soft peak.
Add the 1 cup sugar gradually while whisking until stiff peak and glossy. Remove bowl from the mixer.
Fold in the finely crushed cashew nuts in the meringue in three batches being careful not to deflate the meringue.
Add cornstarch and gently fold again in the meringue.
Transfer your meringue to a piping bag and pipe onto the prepared 5 circular parchment papers. Evenly distribute the meringue to the 5 parchment papers.
Place the meringue on baking sheets (use two if needed). Bake each meringue for 40 minutes or until the top turns a light golden brown. Baking time may differ depending on how many can fit in your oven.
Remove the meringue out of the oven and leave on the baking sheet until it's cool enough to handle. As soon as it's cool enough to touch, carefully peel off the parchment and trim the sides so they're even. Cool completely and cover with a clean kitchen towel before assembly.