To serve creme fraiche fresh, spoon a few dollops over fruit, on top of pies or tarts. You can add creme fraiche to soups for texture. A few swirls of creme fraiche on the top of cream-based soups also looks pretty.
In most recipes, you can substitute creme fraiche for sour cream — especially in baked goods. The pumpkin tart you are referring to is from http://www.177milkstreet.com — the latest venture from Christopher Kimball, founder and formerly of America’s Test Kitchen. According to the recipes, the creme fraiche “gave the filling tang and richness that other dairy products couldn’t match.”
Creme fraiche used to be available only in specialty stores, but you can find it in many grocery stores. At my local store, it’s sold in the deli case near the imported cheese. Some stores keep it near other dairy products. If you can’t find it, be sure to ask for it.
Creme fraiche can be a little pricey, but it’s super easy to make your own, and it’s less expensive.
To make creme fraiche, stir together 1 cup heavy whipping cream (not ultra-pasteurized) and 2 tablespoons buttermilk in a glass jar. Cover with a lid and shake it. (If you want sweetened cream, add 1 to 2 tablespoons of confectioners’ sugar and shake it.) Set it aside at room temperature for 8 to 24 hours or until thickened. There’s no concern leaving it out at room temperature because the bacteria in the buttermilk has a pH level that prevents it from developing any bad bacteria. Once the mixture is thickened similar to sour cream, give it a stir, cover with lid again and refrigerate. You can keep it about 10 days in the refrigerator.
And if you want to amp up the flavor, you can add vanilla extract to crème fraîche before storing or serving.
Preparation time: 30 minutes
Total time: 1 hour, 40 minutes (plus cooling time)
1 recipe single-crust pie dough
1 can (15-oz.) can pumpkin puree
3/4 cup packed dark brown sugar
1/4 cup bourbon
1 cup crème fraîche
3 large eggs
1/4 tsp. kosher salt
1 1/2 cups heavy whipping cream
3 Tbsp. honey
1/2 tsp. grated orange zest
Preheat the oven to 375 degrees with racks in the middle and lowest positions. On a well-floured counter, roll the dough into a 12-inch circle. Wrap the dough loosely around the rolling pin and transfer to a 9-inch tart pan with a removable bottom. Ease the dough into the pan, then trim the edges flush with the rim. Freeze for 15 minutes.
Line the chilled shell with foil and line with pie weights, then place on a rimmed baking sheet. Bake on the lowest rack until the edges are light golden brown, 25 to 30 minutes, rotating the pan halfway through. Remove the foil and weights, then bake until the bottom just begins to color, another 5 to 7 minutes. Remove the pan from the oven and reduce the heat 325 degrees.
Meanwhile, in a 12-inch nonstick skillet over medium-high, combine the pumpkin and sugar. Cook, stirring frequently, until the mixture is thickened, dark and leaves a film on the pan, about 10 minutes. Transfer to a 2-cup liquid measuring cup (the yield should be 11/2 cups). Add the bourbon to the skillet, return to medium-high heat and stir, scraping up any browned bits; add to the pumpkin mixture.
In a food processor, combine the pumpkin-bourbon mixture and creme fraiche; process until smooth. Scrape down the bowl, add the eggs and salt, then process until smooth, about 1 minute.
Pour the filling into the warm crust, smoothing the top. Bake on the baking sheet on the middle rack until the edges start to puff and crack and the center sets, 30 to 35 minutes. Cool in the pan on a wire rack for at least 30 minutes.
Remove the outer metal ring to serve warm or at room temperature with cream.
To make the cream: In the bowl of a stand mixer, combine the heavy cream, honey, and orange zest. Using the whisk attachment, mix on low until frothy, about 30 seconds. Scrape the bowl with a spatula to make sure the honey is incorporated. Mix on medium-high and whip until soft peaks form, 2 to 3 minutes. (Don’t use creamed, thick or crystallized honey for this recipe. In order for the cream and honey to properly mix, a thin, pourable honey is needed.)
From Christopher Kimball's Milk Street, http://recipes.177milkstreet.com/recipes/pumpkin-tart.