Step 1

Combine 1/2 cup sugar and cornstarch in a small saucepan; gradually stir in water until smooth. Stir in blueberries and lemon juice; bring to a boil. Reduce heat to low and simmer, uncovered, until slightly thickened, about 5 minutes. Cover and refrigerate until chilled, about 30 minutes.

Step 2

Preheat oven to 350 degrees F (175 degrees C).

Step 3

Combine graham cracker crumbs, 2 tablespoons sugar, and cinnamon in a large bowl; stir in butter. Pat into ungreased 10x15-inch baking pan.

Step 4

Bake crust in preheated oven until lightly browned, 10 to 15 minutes. Cool completely on a wire rack, then crumble crust.

Step 5

Whisk 1 1/2 cups sugar, pudding mix, whipping cream, milk, and vanilla extract in a large bowl. Fill ice cream freezer cylinder two-thirds full. Freeze according to manufacturer's directions; refrigerate remaining mixture until ready to freeze. Whisk remaining mixture before placing in cylinder to get rid of lumps.

Step 6

Layer ice cream, graham cracker mixture, and blueberry sauce three times in a large bowl; swirl to combine. Freeze until ready to serve.