Preheat oven to 450°.

For peach filling:

Stir together sugar, flour, cinnamon and salt in large bowl.

Add peach slices and gently toss to coat.

Mix together cornstarch, water and lemon juice into slurry and stir into peaches to incorporate.

Butter dish and add peach mixture.

For crumb topping:

Add dry ingredients to medium bowl.

Add butter pieces and combine with hands until crumbly.

Top peaches with half of the crumb topping.

Place in oven and immediately reduce temperature to 350°.

Bake uncovered for 30 minutes.

Add remainder of crumb topping.

Reduce heat to 325°.

Bake until golden and bubbling, another 45 minutes.

Remove from oven and let sit for 15 minutes before serving.

Serve with vanilla ice cream or fresh whipped cream.