Step 1

Place one oven rack on lowest position and another oven rack on middle position. Preheat to 375F. Line a baking sheet with parchment paper and set aside.

Step 2

Gently toss peaches and 1/3 cup sugar together in a large bowl. Let sit for about 45 minutes, gently stirring several times, to allow maceration.

Step 3

Meanwhile, make the Topping: In a large bowl, combine flour, oats, 1/4 cup granulated sugar, brown sugar, cinnamon, ginger, nutmeg, and salt. Whisk to combine. Drizzle vanilla over the top and stir to combine. Add cold butter pieces and use clean fingers to gently work it into a crumbly mixture, with small clumps throughout. Add nuts and gently stir just enough so the nuts stick to the mixture. Mixture should consist of 1/2 inch chunks throughout, with some small loose bits.

Step 4

Scatter topping into a single layer on lined baking sheet. Bake on middle rack until lightly browned and firm, 12-14 minutes, giving it a gentle toss halfway through baking.

Step 5

Drain macerated peaches in a colander set over a bowl and reserve 1/4 cup of the juice (either discard remaining juice or save it for another purpose.) Whisk the reserved juice with cornstarch, lemon juice, salt, cinnamon, ginger, and nutmeg. Fold in the peaches, and gently stir to coat. Transfer peach mixture to a deep 8×8 baking dish. Sprinkle topping over the peaches evenly, pressing down gently if needed. Place on lowest rack and bake until nicely browned and filling is bubbling around edges, about 25-40 minutes (loosely tent the crisp with foil if it starts to brown too quickly.) Let peach crisp cool 15 minutes. Serve while it’s warm from the oven.