Combine the graham cracker crumbs and butter in a medium bowl and mix well.

Place the crumb mixture into an 8-in. springform or loose bottom baking pan. Press the crumbs down with the back of a spoon until you have a compacted, even layer. Put it aside in the refrigerator while you make the cheesecake filling.

Put the cream cheese, powdered sugar, vanilla extract, and lemon juice into a large mixing bowl. Beat until smooth and creamy.

In a separate bowl, whip the heavy cream to stiff peaks. Gently fold the cream by hand into the cream cheese mixture.

Transfer the cheesecake filling on top of the crumb base. Use an offset spatula to smooth the top.

Cover the cheesecake with plastic wrap and refrigerate it for at least 6 hours, but overnight is best.

Meanwhile, add 1 cup of blueberries, lemon juice, and sugar to a medium saucepan to make the blueberry sauce. Stir until the sugar has dissolved, then bring to a simmer for around 5 minutes. Most of the blueberries will break down into a sauce.

Mix the cornstarch with the water and add that to the saucepan along with the remaining half a cup of blueberries. The sauce should be shiny and syrup-like. Remove from the heat. The sauce will thicken even as it cools. Once cool, cover and refrigerate until needed.

When the cheesecake has set, remove it from the baking pan and place it on a plate or cake stand. Pour the cooled blueberry sauce over the top of the cheesecake to cover it completely.

Slice and enjoy!