Put together the peaches: Halve and pit the peaches, then reduce the halves into 1/2-to-3/4-inch-thick wedges. Toss them in a big bowl with the lemon juice, and put aside when you make the salted caramel.
Make the caramel: In a 4-quart ovenproof deep skillet (I’m utilizing my braiser)* stir collectively the sugar and water. Flip the warmth to medium-high and cook dinner, with out stirring, till the floor is evenly effervescent throughout and you start to see golden and medium-brown spots within the effervescent sugar, about 5 minutes. Fastidiously (it’s going to sizzle dramatically) whisk within the butter and proceed to cook dinner till the sauce takes on a fair medium-brown or copper colour, about 2 to 4 minutes. Add the cream a splash at a time, whisking continuously, till it’s evenly blended, and cook dinner for an additional 3 to 4 minutes. Add flaky salt and stir to mix.
Take away from the warmth simply lengthy sufficient to fastidiously ladle 2/3 cup of the sauce fastidiously right into a spouted dish or bowl for later, and set that portion apart.
Parcook the peaches: Return the pan to the range over medium warmth, and add the peaches to the remaining caramel within the pan. The coolness of the peaches will trigger the caramel sauce to grab up a bit, however don’t fret. Simply let the peaches and caramel heat up and the sauce will loosen. Cook dinner peaches and caramel collectively, stirring often, till the peaches have softened barely, about 5 minutes. Stir within the cornstarch or tapioca flour till it disappears.
Make the crisp topping: Combine all the topping components in a big bowl till the butter is evenly dispersed and the combination is rubbly. Sprinkle the topping over the peaches, then switch pan to the oven and bake till the peaches are tender, their juices visibly effervescent across the crisp topping, and the topping is a lightweight, nutty brown, about 20 minutes. Let it cool for 10 minutes, in the event you can bear it, earlier than serving.
To serve: Scoop the crisp into bowls and prime with ice cream and a drizzle of the reserved caramel sauce. In case your caramel sauce has cooled and firmed up, you possibly can heat it up shortly within the microwave — examine each 10 seconds, because it warms and bubbles up shortly — or in a small saucepan on the range.
Do forward: Leftover crisp ought to maintain within the fridge for 5-6 days, however it will be unprecedented. Leftover caramel sauce will maintain for 2 weeks.
* For those who don’t have a pan that goes from range to oven, merely use a big, deep skillet for the caramel and parcooking the peaches, and switch the peaches and sauce to a 4-quart or 9×13-inch baking dish pan for the baking portion, sprinkling the topping on simply earlier than it goes within the oven.
