Pi Day is upon us, and the best way to celebrate is to whip up a tasty treat. This Pi Day is especially significant because it falls on 3/14/15, matching up with the first five digits of pi, which are 3.1415. Here is a great apple pie recipe to help the math geek in all of us honor the ratio of a circle's circumference to its diameter. Apple pie is an iconic American dish and is appropriate for almost any occasion, and what better day to enjoy it than Pi Day! This recipe can get messy as the gooey filling bubbles in the oven, but the author recommends putting a rimmed baking sheet on the rack below the pie to catch some of the runaway filling.

Ingredients

For the crust:

2 1/2 cups all-purpose flour

1 1/4 cups unsalted butter cubed

1 teaspoon salt

1 teaspoon sugar

1/2 cup full fat sour cream

For the filling:

3 pounds good cooking apples such as Fuji, Granny Smith, or Golden Delicious

1 teaspoon lemon juice or apple cider vinegar

3 tablespoons all-purpose flour

1/4 teaspoon ground allspice

1/4 teaspoon ground nutmeg

1 teaspoon vanilla extract

1 teaspoon brandy (optional)

For the egg wash:

1 large egg yolk

1 tablespoon cream

Method:

1. Whisk 2 1/2 cups of flour, 1 teaspoon of salt, and 2 teaspoons of sugar in a large bowl. Add the cubed butter and coat it in the flour mixture. Use your hands to work it in until the mixture is "shaggy" and the chunks of butter are no larger than a kernel of corn. Make a well in the center of the mixture and add the sour cream to it. Use a fork to combine the butter mixture and sour cream until the dough starts to clump. Separate the dough mixture into two separate piles and work them each into a ball and then into a disk. Sprinkle the dough balls with flour, wrap them in plastic, and refrigerate them for at least an hour.

2. While the dough is in the refrigerator, peel, core, and slice the apples into 1/2 inch slices. Put the apples in a large bowl and sprinkle them with lemon juice or apple cider vinegar to keep them from browning.

3. Combine the sugar, flour, and spices in a bowl and add the mixture to the cut apples, coating them evenly. Sprinkle brandy and vanilla extract onto the coated apples and stir to distribute evenly.

4. Preheat the oven to 375 degrees.

5. Remove one crust dish from the refrigerator and let it sit at room temperature for between five and 10 minutes. Place the dough on a flat, floured surface and roll it into a 12-inch circle that is about 1/8 of an inch thick with a rolling pin. Carefully monitor to make sure the dough is not sticking, and if it is sprinkle flour accordingly. Gently place the rolled dough on a 9-inch pie plate and press down to create the crust.

6. Arrange the apple slices in the dough-lined plate, mounding them in the center.

7. Roll out the second disk of dough to the same proportions as the last and place it gently over the apples. Trim off any excess dough, leaving a 3/4 inch overhang from the edges of the dish. Fold the dough under itself so the edges reach right to the rim of the baking dish. Press the ends of the dough together using your thumb and forefinger or a fork.

8. Place egg yolk and cream in a small bowl and use a fork to stir until it is well combined. Use a pastry brush to coat the pie crust in the egg wash. Use a knife to cut slits in the top of the pie.

9. Bake the pie at 375 degrees until the crust begins to brown (about 20 minutes) and reduce heat to 350 degrees. Bake until crust is golden and the juices are bubbling (between 45 minutes and an hour).

10. Transfer to a rack and cool for at least an hour. Serve slightly warm or at room temperature with a scoop of vanilla ice cream if desired.

Recipe credit: Simply Recipes