Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish.
In a large bowl, toss the peaches with the granulated sugar, 2 tablespoons flour, and lemon juice, then spread evenly in the prepared baking dish.
In another bowl, combine the oats, 3/4 cup flour, brown sugar, cinnamon, and salt, then cut in the cold butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
Sprinkle the oat topping evenly over the peaches and bake for 40-45 minutes until the topping is golden brown and the peaches are bubbling.
While the crisp bakes, prepare the maple cream by beating the heavy cream in a chilled bowl until soft peaks form, then add the maple syrup and vanilla and beat until stiff peaks form.
Let the crisp cool for 10 minutes before serving warm with generous dollops of the cold maple cream.