Cut nectarines and peaches in slices or finely chop as preferred. Discard the seeds.
Add sugar and cornstarch(optional), mix well, cover and keep aside for 10-15 mins.
Preheat oven to 350°F or 180°C.
Take a baking dish, add butter in it and keep in the oven, till the butter melts. It will take about 2 mins.
Make batter for cobbler.
Mix pancake mix with milk and sugar. Do not beat the batter, just combine the flour and milk. If there are lumps and leave like that.
In the baking dish with melted butter, transfer fruit filling.
Pour batter over it. Do not mix.
Top with more fruit slices if you want.
Bake in preheated oven for about 30-40 mins.
If baking in small ramekins bowls or pie dishes adjust the baking time accordingly. For small dishes, it should be around 15 mins.
Once done, take out of the oven, serve warm, with your favourite ice cream.
Or,cool completely cover with cling film and refrigerate. Warm in oven, just before serving.