Make the bacon: Preheat oven to 400 degrees (F) and line a baking sheet with foil. Lay bacon down flat and coat with half of the brown sugar. Flip bacon and coat the other side with the other half of brown sugar. Bake for 14-16 minutes, until it's starts to get crispy. Let cool on paper towel and chop into bite size pieces. When bacon is done, reduce oven temperature to 350 degrees (F) to bake the crisp.
Make the filling: In a large mixing bowl, combine the peaches, apples and bacon and stir to combine. Add the flour, sugar, salt and vanilla and mix gently with a rubber spatula to completely coat the fruit. Dump in an 8x8 inch glass or ceramic baking dish and set aside.
Make the topping: in a medium bowl, whisk the brown sugar, flour, rolled oats, cinnamon and salt together, making sure to get all the brown sugar lumps out. Add the butter to the mixture and stir with a rubber spatula until the mixture is crumbly. Evenly sprinkle the topping over the filling.
Bake for 40-45 minutes until the top is golden brown and the filling is bubbling on the sides of the pan. Remove crisp from the oven and place on a wire rack to cool slightly, about 10-15 minutes. Serve warm with a scoop of ice cream.
Tip: finished baked crisp freezes well for up to 2 months. Just thaw overnight and bake on 350 for about 20-25 minutes to warm.