Preheat the oven to 180°C.
Wash the nectarines, remove the pits, and cut them into smaller pieces. Place the prepared nectarines in an ovenproof dish, sprinkle with cornstarch, and mix well.
In a bowl, mix together the spelt flour, sugar, cold butter (cut into pieces), baking powder, vanilla extract, and buttermilk to form a thick dough.
Spoon the prepared dough over the nectarines. There’s no need to cover the entire surface of the fruit completely. Sprinkle the tablespoon of sugar evenly over the top.
Place the dessert in the preheated oven and bake for about 35-40 minutes. The top of the cobbler should be crispy, while the inside remains soft. The dough must be fully cooked. Enjoy!