Start by preheating your oven to 375 degrees.
Mix your dry ingredients in a large bowl: 3/4 cup all-purpose flour, 1/4 cup brown sugar, 1/2 teaspoon salt and 2 tablespoons granulated sugar.
Take your cold butter and cut it into cubes and cut it into the dry mixture. It's best to use a pastry blender if you have one. You want the mixture to be coarse when finished.
Next, add the 1 cup old-fashioned rolled oats. I like to use my hands to combine the oats to the mixture. But, if that makes you uncomfortable, then feel free to use a large spoon. You want it to be clumpy!
Put in the fridge or freezer until you're ready for it.
Now it's time to prepare your apples. Start by washing and cubing your apples. Put them in a bowl and toss them with the 2 1/2 tablespoons (or so) of lemon juice, 3/4 teaspoon cinnamon and remaining granulated sugar.
Transfer the apples to a shallow baking dish or individual ramekins. You want the baking dish (or ramekin) filled about 1/2 way with apples.
Then put a layer of the topping mixture over the apples.
Put the baking dish(es) on a rimmed baking sheet and bake until golden brown and bubbling a little - approx 60 minutes.
Allow them to cool for 10-15 before serving. Top with whipping cream!