Oil an 8 x 8-inch baking pan

Combine the jam, water, gelatin and citric acid in a 3-quart saucepan. Stir constantly and slowly over medium-high heat with a heatproof spatula until syrup reaches 22*F. Pour into the prepared pan, and skim off any foam with a spoon. Let cool to room temperature, and then refrigerate until firm, about 3 hours.

Combine the powdered sugar and cornstarch in a bowl. Unmold the jelly onto a cutting board lined with parchment paper. Cut into 1-inch squares and roll in the powdered sugar and cornstarch mixture. Store in an airtight container.