Preheat your oven to 325°F and lightly coat a 9x13-inch baking dish with cooking spray. This helps the cake release easily after baking. Set the dish aside while preparing the filling.
Melt a small portion of the butter in a large skillet over medium-high heat. Add the peaches, brown sugar, cinnamon, salt, lemon juice, vanilla, and bourbon if using. Cook for about 6–8 minutes until the peaches soften and the juices become slightly syrupy.
Transfer the warm peach mixture into the prepared baking dish. Drizzle the hot honey evenly over the fruit. Sprinkle the dry yellow cake mix evenly across the top without stirring anything together.
Scatter the remaining butter pieces evenly across the cake mix. Try to distribute them well so the topping browns evenly while baking. The butter melts into the cake mix, creating a crisp, golden crust.
Place the baking dish in the oven and bake for about 40 minutes. The top should become beautifully golden while the fruit filling bubbles around the edges. Resist opening the oven too often during baking.
Allow the cake to rest for about 10 minutes after removing it from the oven. Spoon the warm dessert into bowls and top with vanilla ice cream. Finish with another drizzle of hot honey if you enjoy extra sweet heat.