Nectarine and Blackberry Crisp
Of all the stone fruits, I find that nectarines have a more complex flavor profile than others. They’re delicious on their own but bake beautifully without losing their seductive nuance. Combining them with blackberries creates the perfect stage for both fruits to shine.
Make the filling
Place an oven rack in the middle position and preheat the oven to 350ºF (180°C).
In a small saucepan over high heat, combine 1/2 cup of the granulated sugar with 1/4 cup of the water. Cook until the sugar dissolves and becomes syrupy, 5 to 8 minutes.
Add the blackberries and cook, stirring with a wooden spoon, to release their juices, about 5 minutes. In a small bowl, dissolve 1 tablespoon of the cornstarch in the remaining 2 tablespoons of water and add to the berries. Stir constantly until the compote has thickened, 2 to 3 minutes. Transfer to a separate container and let cool completely.
While the compote cools, cut each nectarine into eight equal wedges, discarding the pits. In a large mixing bowl, toss the nectarine wedges with the remaining 2 tablespoons of sugar, the remaining 1 tablespoon of cornstarch, and the sour cream. Let the nectarines macerate at room temperature while you make the topping.
Make the topping
In a food processor, pulse the cold butter, oats, and brown sugar until a coarse, irregular meal with pea-size butter pieces forms. To assemble the crisp, gently combine the cooled berry compote with the nectarine mixture using a spatula. Dump the fruit filling into a 9-inch (23-cm) round or 9-by-9-inch square baking dish and top with a generous layer of oat crumble. Place the baking dish on a rimmed baking sheet to catch the drips and bake for 25 minutes. Rotate the baking sheet and bake until the top is golden brown and the juices start to form thick bubbles, 20 to 30 minutes more. Don’t be alarmed if the thick juices spill over and drip a little on the sides of the baking dish—this is a sign of a jammy filling. Rotating the baking sheet halfway through the baking process will ensure that the crisp bakes evenly.
The crisp will benefit from cooling for 20 minutes before digging in. Serve warm with a scoop of vanilla ice cream. This crisp reheats very well, so if you plan to serve it later, let cool completely and reheat in a preheated 350ºF (180°C) oven for 10 to 15 minutes.
*How do I know when my nectarines are ripe?
Nectarines (and peaches, and most other stone fruit) have a few key signs to look for when you're craving them right away. They'll be firm to the touch with a little give—not squishy and not solid. They should smell sweet. No fragrance means that they're going to need a little more time. Ripe nectarines should be a deep color that ranges from yellow to red (depending on the variety, of course), with no green spots. Finally, you want them to have a rounder bottom, not unlike a peach. Nectarines still have more of a point than peaches but you still want to see a gentle curve.
And much like peaches, nectarines will continue to ripen off the tree so if you can only find ones that are still a little firm, take heart knowing that you can still use them. Unfortunately, it will still take a little time, up to 4 days, depending on how young they are. Placing them in a paper bag and letting them rest on your counter, out of sunlight, for a day or two will help. Putting banana in the bag will help, too. The ethylene gas produced by the banana will urge them along.