Preheat oven to 325°F. Line a baking sheet with parchment paper.

In a small bowl, whisk together sugar and cornstarch; set aside.

Using an electric mixer, whip egg whites on medium-high speed until soft peaks form, about 3 minutes.

Continue to whip, gradually adding sugar mixture 1 tablespoon at a time, until stiff peaks form.

Beat in lemon juice.

Spoon mixture into a large piping bag or a large resealable plastic bag. Cut open tip of piping bag about 1/2 inch wide.

Pipe ghost mounds about 2 inches high onto the prepared baking sheet. Use dried blueberries and/or currants to make eyes and mouths.

Place in the oven and lower heat to 225°F. Bake for 1 hour.

Turn the oven off and prop the door open, using a wooden spoon to keep the door open if needed.

Let meringues cool completely in the oven.

Meringue ghosts will keep in an airtight container at room temperature for up to 3 days.