01 -
Preheat oven to 375°F.
02 -
Wash, slice, and optionally peel the peaches.
03 -
In a large mixing bowl, combine sliced peaches, ¾ cup granulated sugar, lemon juice, cornstarch, vanilla extract, and cinnamon if using. Stir gently and let sit for 10 minutes to release juices.
04 -
In a separate bowl, mix the flour, ½ cup sugar, baking powder, and salt.
05 -
Add cold cubed butter to the flour mixture. Use a fork or pastry cutter to cut in the butter until the mixture is crumbly and resembles coarse sand.
06 -
Pour in ¼ cup boiling water and stir just until a thick dough forms.
07 -
Pour the peach filling into a 9-inch square baking dish or similar-sized pan. Spoon the topping over the peaches in small mounds, leaving some gaps. Flatten large mounds slightly with the back of the spoon.
08 -
Sprinkle coarse sugar on top if desired.
09 -
Bake for 38 to 42 minutes, until the topping is golden brown and the peach filling is bubbly around the edges.
10 -
Remove from oven and let cool for at least 15 minutes before serving. Serve warm or at room temperature, plain or with vanilla ice cream or whipped cream.