Blueberry Cobbler (ATK)

• servings: 8

Ingredients

BISCUIT TOPPING

1½ cups (7½ ounces) all-purpose flour

5 teaspoons sugar

1½ teaspoons baking powder

½ teaspoon baking soda

½ teaspoon salt

¾ cup buttermilk

6 tablespoons unsalted butter, melted, plus 1 tablespoon unsalted butter

FILLING

¾ cup (5½ ounces) sugar

1 tablespoon cornstarch

1½ teaspoons grated lemon zest plus

1 tablespoon juice

Pinch salt

30 ounces (6 cups) blueberries

Directions

1. Adjust oven rack to middle position and heat oven to 375 degrees. Line rimmed baking sheet with parchment paper.

2. FOR THE BISCUIT TOPPING: Whisk flour, 1 tablespoon sugar, baking powder, baking soda, and salt together in large bowl; set aside. Stir buttermilk and melted butter together in 2-cup liquid measuring cup (butter will clump; this is OK); set aside.

3. FOR THE FILLING: Combine sugar, cornstarch, lemon zest, and salt in large bowl. Add blueberries and lemon juice and mix gently with rubber spatula to combine. Transfer berry mixture to 8-inch square baking pan or ceramic dish. Place pan on prepared sheet and bake until filling is hot and starting to bubble around edges, about 25 minutes. Transfer sheet to wire rack and gently stir berry mixture. Increase oven temperature to 475 degrees.

4. Once oven reaches 475 degrees, add buttermilk mixture to flour mixture and stir with rubber spatula until just incorporated. Using greased ¼ cup dry measuring cup, drop 9 scant scoops of dough, evenly spaced, onto hot berry filling. Sprinkle tops with remaining 2 teaspoons sugar.

5. Bake until biscuits are golden brown and toothpick inserted in center biscuit comes out clean, 12 to 14 minutes. Melt remaining 1 tablespoon butter and brush over biscuits. Let cobbler cool on wire rack for at least 30 minutes. Serve.

Notes

You can substitute unthawed frozen blueberries for fresh berries, but increase the baking time in step 3 to 40 minutes.

Buying Blueberries Our recipe calls for fresh blueberries, but frozen are cheaper and work well here, too (see recipe headnote). In summer, some markets carry small wild blueberries, which have outsize flavor and are fantastic eaten out of hand. But we don't like to bake with them, as their small size means they break down more easily, result- ing in a filling with a homogeneous texture. We recommend sticking with cultivated, full-size blueberries for most baking applications.

Bake the Fruit First It's important that the fruit is hot when you drop the biscuit batter on top— otherwise the bottoms of the biscuits will be undercooked and gummy.

Pro Baker's Trick When portioning batter or cookies with a measuring cup, greasing the cup first makes for an easy release. We like to grease measuring cups with vegetable oil spray, but an even smear of vegetable oil or butter works, too.

Add Lemon to the Filling Lemon enhances the fruit's flavor and balances the sweetness in virtually any fruit dessert.

Better Butters

Our recipe testers sometimes ask us why we use unsalted butter in recipes as we do in our biscuit recipe here). The reason is simple: Different salted butters contain different amounts of salt, so by calling for unsalted butter, we can control the salt level to make sure our recipes work. In addition, salted butters almost always contain more water than un-salted butters and the extra water can make for baked goods that are a bit gummy. Our favorite "fancy" (and expensive) supermarket unsalted butter is Plugrá European-Style, and Land O'Lakes Unsalted Sweet Butter is our favorite everyday option.

Mix Biscuits at the Last Minute Wait until just before baking to mix the premeasured wet and dry biscuit ingredients. This ensures that the leaveners (which are activated by liquid) will be at full strength, contributing to a light and fluffy topping.

Bake on a Rimmed Baking Sheet Lined with Parchment Cobbler filling can bubble over and make a mess of your oven. Baking the cobbler on a rimmed baking sheet is good; covering the surface of the sheet with parchment paper is even better.

Clumpy Batter Leads to Steam (and Fluffy Biscuits) Traditional biscuit recipes call for cutting cold fat (butter or shortening) into the flour before adding the liquid. Drop biscuits— including the ones we top the cobbler with here-are easier: Just stir all the ingredients together, drop, and bake. But some drop biscuits can turn out dense and compact, without the flakiness and lightness we want in a biscuit. To create light and flaky drop biscuits, we add melted butter to cold buttermilk. When combined with the cold buttermilk, the butter forms clumps. As those clumps of butter melt during baking, the water in the butter evaporates and creates steam, which lightens the biscuits.

Can I bake this cobbler in a glass dish? No. Be sure to use an 8-inch square ceramic dish or metal baking pan for this recipe. Do not use a Pyrex (or other glass) dish, as it is not safe at the 475-degree oven temperature we call for.

CHOOSE WISELY Our winning square baking pan is the Williams Sonoma Goldtouch Nonstick 8-Inch Square Cake Pan ($21.00) .

What if I don't have buttermilk? If you don't have buttermilk on hand, the test kitchen has two options for you. The first option is to substitute clabbered (or acidulated) milk for the buttermilk. To make clabbered milk, stir 1 tablespoon of (preferably fresh) lemon juice into 1 cup of milk (we don't recommend skim milk here, but all other types will work just fine). Let the mixture sit for 10 minutes to thicken. For a second, nondairy option, you can substitute soy milk or oat milk for the regular milk (note that clabbered soy milk will thicken like regular milk but oat milk will not).

Step by Step

1. Prepare oven and sheet Adjust the oven rack to the middle position and heat the oven to 375 degrees. Line a rimmed baking Sheet with parchment paper. Why? The parchment protects the baking sheet (and the oven) in case the filling bubbles over.

2. Mix dry ingredients Whisk the flour, sugar, baking powder, baking soda, and salt together in a large bowl; set aside. Why? The biscuits need to be stirred together at the last minute later in the recipe, so we prepare the dry ingredients ahead of time.

3. Mix buttermilk and butter Stir the buttermilk and melted butter together in a 2-cup liquid measuring cup; set aside. Why? Mixing melted butter into cold buttermilk creates clumps of butter that melt in the oven, creating steam that produces a flaky, light interior.

4. Make blueberry filling Combine the sugar, cornstarch, lemon zest, and salt. Add the blueberries and lemon juice and mix gently. Why? Cornstarch thickens the filling without creating a starchy texture; lemon helps balance the sweetness with a touch of acidity.

5. Bake berries

Transfer the berry mixture to a square baking pan. Place the pan on the prepared sheet and bake until the berries are hot and start- ing to bubble around the edges. Why? We prebake the filling to ensure that it is hot when we add the biscuit topping

6. Stir berries and turn up oven

Transfer the sheet to a wire rack

and increase the oven tempera- ture to 475 degrees. Stir the berry mixture while the oven heats. Why? The biscuits need a hotter oven to rise and brown. We gently stir the berry mixture to even out its overall temperature.

7. Stir together biscuit dough Once the oven reaches 475 de-

grees, add the wet ingredients to the dry; stir until just incorporated. Why? Baking soda is activated as soon as it's mixed with liquid, so it's best to wait until just before baking to combine the buttermilk mixture and the flour mixture.

8. Scoop and drop biscuits Using a greased ¼-cup dry measuring cup, drop nine scant scoops of dough, evenly spaced, onto the hot berry filling. Why? The residual heat from baking the berry filling helps cook the biscuit dough through from the bottom up.

9. Sprinkle with sugar and bake Sprinkle the tops with sugar and bake until the biscuits are golden brown and a toothpick comes out clean, 12 to 14 minutes. Why? A final sprinkling of sugar before the cobbler goes into the oven creates crispy, craggy, golden-brown tops on the biscuits.

10. Brush with butter Melt the remaining butter and brush it over the biscuits. Let the cobbler cool on a wire rack for 30 minutes. Serve. Why? Brushing the biscuits with a little melted butter while they're hot keeps them moist and adds extra buttery flavor.