In a medium bowl, whisk together the all-purpose flour, 1/4 cup brown sugar, and baking powder. Pour in the heavy whipping cream, melted butter, and 1/2 tsp vanilla extract, then gently fold the mixture together until just combined into a thick, biscuit-like dough. Don't overmix—lumps are okay and will give you a more tender topping. Set the dough aside at room temperature so it stays workable for later assembly.

Preheat your grill to 400°F. Place the peach wedges directly on the grill grates and cook for about 5 minutes, flipping halfway through, until they develop light char marks and become slightly softened. The peaches don't need to be cooked through at this point—they'll finish cooking under the foil later. Let them cool for a few minutes, then transfer to a cutting board.

In a medium bowl, combine the 1/2 cup brown sugar, 2 tbsp flour, cinnamon, nutmeg, and 1/2 tsp salt. Add the grilled peaches to this mixture along with the lemon juice and 1 tsp vanilla extract, then gently toss until all peaches are evenly coated. Transfer this filling to a cast-iron skillet or aluminum foil pan sized for your grill, and distribute the 2 tbsp butter pats evenly over the top. I like to scatter the butter directly over the peaches rather than stirring it in—this way it melts into pockets of richness throughout the filling.

Cover the skillet tightly with aluminum foil and place it on the grill (keeping the grill at 400°F). Cook for 15 minutes—this allows the peaches to release their juices and the filling to heat through. The foil traps heat and steam, creating the perfect environment for the fruit to soften and the flavors to meld together.

Carefully remove the foil from the skillet—watch out for steam! Drop spoonfuls of the cobbler topping dough from Step 1 over the peach filling, spacing them out slightly so they have room to puff up (they don't need to cover the filling completely). Return the skillet to the grill, uncovered, and cook for 12-15 minutes until the topping is golden brown and a toothpick inserted into the thickest part of a biscuit comes out clean. I find that rotating the skillet halfway through the cooking time helps ensure even browning, especially if your grill has hot spots.

Remove the skillet from the grill and let the cobbler rest for 10 minutes—this allows the filling to set slightly and prevents it from running all over the plate. Serve warm, ideally with a generous scoop of vanilla ice cream or whipped cream on top.