Maple Buttermilk Pie with Rye Crust

Being from a region of the country wholly nonproximate to the South, I hadn't even heard of buttermilk pie until a few months ago. Bobbie with her sweet tooth was, naturally, responsible for the curiosity after she told me about chess pie, of which I was also unaware but by which I'm now equally intrigued. The two are related, and both seem to be the type of dessert that was made with whatever the ladies of the day had handy in their kitchens. As it were, Crafty Bastards left us with a fair amount of unused buttermilk, and this pie was a perfect cool-weather solution on a weekend saturated with the most excellent visitors.

For the skeptics and the west coasters, buttermilk pie comes out of the oven with a lightly caramelized top and a sweet, thick, custardy inside. The maple in this version -- that I gather is nontraditional -- complemented the caramelization, and the whole thing tasted a bit like tangy dulce de leche. It's a little ugly and a little stunning and wholly deserving of your leftover (or new!) buttermilk.

Maple Buttermilk Pie with Rye Crust
Adapted from 101Cookbooks

Crust
Makes enough for one double-crust or two single-crust pies.
I doubled the salt and added sugar. How predictable!

Scant 2/3 cup rye flour (75 g.)
1 1/2 cups all-purpose flour
1.5 teaspoons granulated sugar
1/2 teaspoon fine-grain sea salt
8 oz. (two sticks) unsalted butter, very cold and cut into half-inch pieces
1/4 to 1/2 cup very cold beer (!!!) or water, or slightly more (amount will depend on the weather; I used 1/2 cup plus 1 tablespoon beer)

1. Put the flours, sugar, and sea salt in the bowl of your food processor (or in a bowl if you don't have a processor). Pulse once to mix and sprinkle with little cubes of butter. Using short pulses (or a pastry blender), mix the butter into the flour until the crumbs range in size from large peas to oatmeal.

2. Turn the flour mixture out into a large shallow bowl. Drizzle 1/4 cup of the liquid over the flour-butter mix and cut through it with a rubber spatula to blend. If the mixture still looks dry, add more liquid one tablespoon at a time until it's pretty shaggy and holds cohesive when you squeeze it together. Divide dough into two equal pieces, wrap each in plastic wrap, flatten slightly, and refrigerate for at least one hour before rolling.

3. If you only need one crust for now, triple wrap the second in plastic and freeze for up to a week. Or! Make two pies. Rye crust is delicious with just about any filling. You could also halve the recipe, or check the archives for a different crust if you can't halve weights.

Filling
1 teaspoon lemon zest
2 tablespoons golden brown sugar
6 egg yolks
1/4 cup all-purpose flour
2/3 cup real maple syrup (pref. grade B)
2 cups buttermilk (pref. whole fat)
1 teaspoon vanilla
scant 1/2 teaspoon fine-grain sea salt
large-grain sugar for sprinkling

1. Preheat oven to 375 F with a rack in the bottom third. Roll out one hunk of the pie dough hunks on a lightly floured surface into a 12-inch round. Guide it into a 9-inch pie dish, and trim the crust so that there is a one-inch overhang. Tuck the overhang under itself, then flute it with your fingers or crimp with a fork. Prick the bottom of the crust with a fork a bunch of times. Line the bottom and sides with one large piece of parchment or buttered foil and fill with pie weights or dried beans. Bake for 20 minutes, remove the weights and parchment, and bake for 10 minutes more until golden. Allow crust to cool as long as possible.

2.  Now mix the filling! In a large bowl, whisk the lemon zest, brown sugar, yolks, and flour until mixture is free of lumps. Slowly add the maple syrup, whisking, then the buttermilk, vanilla, and sea salt.

3. Dial the oven down to 325 F. Put cooled crust (or cooled-ish) on baking pan lined with foil, and pour the mixture into the shell. Bake until filling is somewhat firm around the edges and set in the center, about one hour. Filling will puff up like a crazy souffle then deflate as it cools. Allow pie to cool on a rack, sprinkle with large-grain sugar, and enjoy! Ours was finish in 24 hours, but we did leave it covered on the counter to great success during that time. If you're keeping it out for longer than a day, cover with plastic and put in the fridge.