Peach crumble with oatmeal-brown sugar topping

Interrupting my Japanese food and literature binge, this afternoon I made an Anglo-Saxon favorite: peach crumble, sometimes known as peach crisp. Well, it's a favorite in England and the US, so doesn't that make it Anglo-Saxon?

For the record, I was reading another Japanese novel until I started cutting up some nice ripe local peaches. These were not the peaches I bought last Wednesday because we ate them all by Friday. These are newer local peaches. We had lots of protein for breakfast and lunch, so this was our entire dinner. And here's the recipe:

Topping

3/4 cup packed brown sugar
3/4 cup non-instant rolled oats
1/2 cup flour
1 teaspoon cinnamon
1/4 teaspoon powdered vanilla (if you have it)
3/4 stick unsalted butter

Measure the dry ingredients into a bowl and mix together. Add the butter using 2 knives at first to cut it into pieces, then fingers. The butter should be incorporated until it has moistened the dry ingredients and the mixture is in small lumps. Set aside while making filling.

Notes:

• Butter should be cold but not frozen. Defrost frozen butter on the "poultry" setting in the microwave, using slightly less time than the default.
• This topping would also be fine for apple crisp, though I would suggest adding a few walnuts or pecans to topping for sliced apples, and maybe a few raisins.  

Peach filling

3-4 large or up to 6 small peaches (2 to 3 lbs)
1/3 cup packed brown or white sugar
1 1/2 teaspoons cornstarch
Fresh-squeezed lemon juice
1/4 teaspoon vanilla extract
pinch salt

Mix sugar and cornstarch in a bowl. Slice peaches and drizzle the slices with a few drops of lemon juice and vanilla extract. Toss peaches with sugar mixture. Spread in 8 by 8 inch baking dish. Cover with topping.

Bake at 435º for 25 minutes. Wait around 20 minutes (or a bit more if you can wait) to allow the crumble set up a little. Serve with vanilla ice cream or whatever you like.

Left: peach crumble just out of the oven.
Right: the peaches in the mixing bowl; the topping; and the peaches in the baking dish before adding the topping.