Light and refreshing for blackberry season!
Combine first 3 ingredients in a bowl and toss with a fork until moist. Press into the bottom and up the sides of a 9-inch springform pan coated with cooking spray.
Combine 3 cups blackberries and fresh lemon juice in a blender or food processor and process until smooth. Strain mixture through a sieve over a bowl and discard the solids.
Place salt and egg whites in a large bowl and beat with a mixer at high speed until foamy. Combine sugar and 6 T. water in a medium saucepan and bring to a boil. Cook without stirring until thermometer reaches 250 degrees. Gradually pour (be careful not to pour all at once or the sugar mixture will just harden on the sides of your mixing bowl) the hot sugar mixture into the egg white mixture, beating at medium speed, then at high speed until stiff peaks form. Gently fold in the blackberry mixture; pour into the prepared crust, cover and freeze for 8 hours or overnight. Let stand for 5 minutes at room temperature before serving. Garnish with fresh blackberries and mint; dollop with fresh whipped cream if desired. 12 servings
1 1/2 cups graham cracker crumbs (about 12 cookie sheets)
1/4 butter, melted
3 T. sugar
3 cups fresh blackberries
1/4 cup fresh lemon juice
1/4 tsp. salt
4 large egg whites, at room temperature
1 cup plus 2 T. sugar
6 T. water
Fresh blackberries and mint sprigs for garnish, as desired