• Preheat the oven to 400°F, and lightly grease a deep-dish 9" or standard 10" pie plate.

For the Apple Crisp Oat Topping

• In a mixing bowl, combine the brown sugar, flour, oats, cinnamon, and salt in a mixing bowl. Stir to mix.
• Add the diced, cold butter. Work the butter into the sugar-flour mixture with your fingers until the texture resembles coarse, damp sand. Refrigerate until ready to use.

For the Apple Filling and to Finish the Apple Oat Crisp

• Peel the apples and cut them into wedges. Put the apple slices in a large mixing bowl as you go.

  PRO TIP: Here's how to cut apples for apple pie or crisp. Using a sharp knife on a cutting board, place each apple right-side up so that the stem faces upward. Slice the apple on either side of the core, creating two halves. Place the remaining apple on the cutting board, and cut the remaining flesh on either side of the core. Discard the core. Cut the two apple halves into thirds or so, creating wedges. It doesn't have to be perfect.
• Combine the sliced apples with the sugar, flour, salt, cinnamon, and lemon juice.

  PRO TIP: Almost a secret ingredient, lemon juice subtly enhances and brightens the flavor of fruit, much like how coffee enhances the flavor of chocolate.
• Pour the apples into the deep-dish 9" pie pan, or a standard 10" pan, or similarly sized baking dish. Press the apples lightly to settle them evenly into the pie plate and eliminate any large air pockets.
• Use a large spoon or your hand to cover the apples completely with the apple crisp oat topping. Use it all up; you want it to be a substantial layer. Do not worry if some of the crumble falls into gaps in the apples.
• Bake the apple crisp for 45 minutes to 1 hour on the center rack of the oven, until the apples are bubbly and the crisp is a golden brown.

  PRO TIP: Many apple pies are baked at 425°F. But this bakes at 400°F to slow browning, due to the high sugar content of the oatmeal topping. If your crisp starts too brown too much before the apples are cooked, lightly tent the top of the crisp with foil.

  PRO TIP #2: Place a rimmed baking sheet or aluminum foil beneath the crisp as it bakes to catch any juices that bubble over.
• Let the finished apple crisp cool, uncovered, for about 20 minutes. Serve with a scoop of vanilla ice cream or generous dollop of fresh whipped cream.