Preheat your oven to 350°F (175°C). In a large mixing bowl, combine 2 cups of all-purpose flour, 0.5 cup of granulated sugar, and 0.5 teaspoon of kosher salt. Cut in 0.75 cup of cold and cubed unsalted butter until the mixture resembles coarse crumbs. Press this mixture evenly into the bottom of a lined 9x9 inch baking pan and bake for 15-18 minutes until the crust is just pale golden.

While the shortbread base is baking, wash and slice 4-5 fresh peaches. In a bowl, toss the peach slices with 1 tablespoon of sugar and 2 tablespoons of cornstarch until well coated. Once the crust is ready, layer the peach mixture over the baked shortbread base, spreading it evenly.

In another mixing bowl, combine the remaining 0.5 cup of flour, 1.5 cups of old-fashioned rolled oats, 0.5 cup of packed brown sugar, and 1.5 teaspoons of ground cinnamon. Add 0.25 cup of cold, cubed unsalted butter to the dry ingredients, working it together until it forms clumpy crumbs.

Spread the crumble mixture evenly over the peach filling, ensuring it covers the fruit completely. Place the pan in the oven and bake for an additional 30-35 minutes, or until the topping is golden brown and the filling is bubbling around the edges.

Once baked, allow the Peach Crumble Bars to cool in the pan on a wire rack for at least 20 minutes. Drizzle wildflower honey generously over the top, allowing it to run down the edges.