Bubby’s buttery blueberry pie with crème fraîche

Combine the cream and buttermilk (but not the sugar) in a jar with a tight-fitting lid and place it in a warm (70° to 80°F) spot, such as the top of the refrigerator. Allow it to sit, undisturbed overnight or until thickened but still pourable. Chill it and it will become the consistency of sour cream.

To use, add 1 tablespoon sugar for each cup of crème fraîche needed and whisk lightly by hand. Sweeten only the portion you plan to serve immediately.

In a large bowl, mix the crumbs, sugar, and salt. Add the butter and stir until evenly combined. (You don’t need to worry about overworking a crumb crust.)

Press this mixture into an 8-to-10-inch pie tin with your fingers, striving to make the distribution and thickness of the crumb crust as even and compacted as possible. If you’re using an aluminum tin and you have a spare, press the spare tin on top of the crumb crust and put pressure on the top tin to make the crumbs more compact. Remove the second aluminum tin. Refrigerate the crust for 30 minutes.

Preheat the oven to 350º F. Bake the crust for 8 minutes uncovered, until it begins to smell good and is lightly browned near the crust edge. Cool at room temperature and refrigerate (or freeze for an ice-cream pie) before filling.

One day in advance, make the crème fraîche. If using a pastry dough, fully blind-bake the crust until it is golden brown; set aside to cool. For a crumb crust, follow recipe instructions.

Place 3 cups of the blueberries in a large bowl and set aside. Place the remaining cup of blueberries in a saucepan with ½ cup of the water and bring to a boil. Simmer the berries for 3 to 4 minutes, until they are cooked and liquidy. Smash any remaining berries with a spoon.

In a separate bowl, mix the cornstarch and remaining 2 tablespoons of water until smooth. Add the cornstarch slurry, sugar, and lemon juice to the sauce and stir until the sauce is boiling lightly, the starchy cloudiness disappears, and the sauce thickens to a shiny blue-black, about 2 minutes. Pour the hot sauce over the fresh blueberries and stir gently until all of the berries are coated. Pour the blueberries into the pie shell and let the pie set up for 2 hours at room temperature.

The pie is best served the day it’s made, with a dollop of crème fraîche on the side. Store the pie uncovered in the refrigerator up to 3 days.