Yogurt-Berry Jelly Squares

Coat two 8x8x2-inch baking pans with cooking spray; wipe out excess. Set aside.

In a small bowl, sprinkle two envelopes of gelatin over 1/2 cup cold water. Let stand 5 minutes. In a small saucepan, combine blueberries, 1/3 cup sugar, 1 teaspoon lemon juice, a pinch of salt and an additional 1/2 cup water. Cook and stir over medium heat until sugar is dissolved. Bring to boiling then reduce heat and simmer, uncovered, for 3 minutes or until blueberries have partially broken down. Remove from heat. Add gelatin mixture to blueberry mixture, stirring to dissolve. Strain mixture through a fine-mesh sieve. Pour into one of the prepared pans. Repeat process using frozen raspberries. Chill pans, covered, 8 to 24 hours.

Coat a 13x9x2-inch baking pan with cooking spray; wipe out any excess. Remove the fully set berry mixtures from the refrigerator and chop into roughly 1/2-inch pieces. Gently toss all the pieces together in the prepared baking pan and place it in the refrigerator.

In a medium saucepan, sprinkle the remaining three envelopes of gelatin over 1/2 cup cold water. Let stand 5 minutes. Cook and stir over medium heat until gelatin dissolves. Add 1/2 cup sugar. Cook and stir until sugar dissolves. Whisk in yogurt, milk, remaining 1 teaspoon lemon juice, the vanilla and 1/4 teaspoon salt. Pour mixture over the berry cubes. Chill, covered, 4 hours or overnight. Cut into squares to serve.