3 1/2 cups blueberries (18 ounces), divided
3/4 cup pure maple syrup (preferably Medium), divided
1 cup chilled heavy cream
1 teaspoon fresh lemon juice
6 ounces thin ginger cookies, coarsely crumbled
Cook 2 1/4 cups (3/4 pound) blueberries with 1/2 cup maple syrup in a 2-quart heavy saucepan over medium heat, stirring occasionally, until blueberries have burst, 3 to 8 minutes. Cool in an ice bath, stirring occasionally.
While blueberry mixture cools, beat cream with remaining 1/4 cup maple syrup in a bowl using an electric mixer until it just holds stiff peaks.
Stir lemon juice and remaining 1 1/4 cups blueberries into cooled blueberry-maple mixture.
Spoon about 2 tablespoons blueberry mixture into each of 6 glasses and top with half of crumbled cookies and half of whipped cream. Repeat layering of remaining blueberry mixture, crumbled cookies, and whipped cream.