2 (6-ounce) packages blackberries
2 tablespoons freshly squeezed lemon juice
1/2 cup granulated sugar
1 cup Concord grape juice
Gold star and moon sprinkles (optional)
Blend the blackberries and lemon juice in a food processor or blender until smooth. Strain through a fine-mesh strainer set over a bowl, pressing down on the solids to extract as much purée as possible. Discard the seeds and solids.
Add the sugar to the purée and stir until dissolved. Add the grape juice and stir to combine. Pour the mixture into ice pop molds and freeze until solid, about 6 hours or overnight.
Remove the pops from the molds and sprinkle with gold stars just before serving, if using.