Preheat the oven to 350°F.
Place the stick of butter in a 9x9-inch square baking dish and put it in the oven for 3-4 minutes until fully melted. Once melted, remove from the oven and set aside.
In a medium mixing bowl, whisk together the flour, baking powder, and salt. Add the sugar and whisk to combine.
Pour in the buttermilk, vanilla extract, and lemon extract, whisking just until combined.
Pour the batter evenly over the melted butter in the pan (do not stir).
Spoon the lemon pie filling over the batter.
Bake at 350°F for 45-55 minutes, or until the edges of the cobbler are golden brown.
Allow to cool slightly before serving.