Combine peaches, sugar, flour, cornstarch, lemon juice and sugar into the instant pot and stir. Then add water.
Press the "Saute" button, let the mixture come to a boil. Allow it to cook for 5 minutes then push cancel to stop the boiling.
Mix the flour, sugar, baking powder and salt together. Cut in the butter with a pasty cutter until butter is pea sized. Stir in the buttermilk.
Add spoonfuls of cobbler topping onto the filling. Then push "Pressure Cook" on high, and set timer for 20 minutes.
When the cooking cycle completes allow for a full natural release. Allow the cobbler to cool then coop out of Instant Pot and serve with vanilla ice cream or whip cream.