Preheat the oven to 350°F and set a large-rimmed baking sheet aside.
While the oven is preheating, place the butter in a 9x13-inch casserole dish and transfer the dish into the oven while it's preheating to melt the butter.
1/2 cup (113g) unsalted butter
While it’s melting, whisk together the flour, granulated sugar, and baking powder. Whisk in the milk and vanilla until combined.
1 1/3 cup (160g) all-purpose flour, 1 cup (200g) granulated sugar, 2 teaspoons baking powder, 2/3 cup (157ml) whole milk, 1 teaspoon vanilla bean paste or vanilla extract
When the butter is melted, carefully remove it from the oven and whisk the salt and optional bourbon into the butter. Drop small Tablespoonfuls of the batter evenly over the melted butter mixture. Do not mix.
1 teaspoon fleur de sel or flaky sea salt, 1/4 cup (59ml) bourbon
Sprinkle the pecans in an even layer over the batter then cover the pecans evenly with the brown sugar.
1 1/2 cups (188g) chopped pecans or pecan halves, 1 cup (213g) light brown sugar
Boil the water in a saucepan over medium-high heat or microwave on high for about 1 minute. Carefully pour the very hot water evenly over the cobbler. Do not stir.
1 1/2 cups (355ml) boiling water
Carefully place the baking dish on a large rimmed baking sheet. Transfer the baking sheet and pecan pie cobbler to the preheated oven and bake for 30-35, or until the top is golden brown and looks dry and set.
Cool on a wire rack for 30-45 minutes before serving.
While it’s cooling, make the vanilla bean whipped cream. Using a hand mixer or a stand mixer fitted with a whisk attachment, whip the heavy cream, sugar, and vanilla bean seeds on medium-high speed until medium peaks form, 3-4 minutes.
Homemade whipped cream and/or vanilla ice cream for serving, 1 cup heavy whipping cream, 2 Tablespoons granulated sugar, 1 vanilla bean seeds removed
Serve the pecan pie cobbler warm with whipped cream and optional vanilla ice cream.