Preheat the oven to 220ºC/425ºF and spray donut pan with non-stick spray.
Mix together the eggs, milk, sour cream, melted butter, oil and vanilla.
Stir in the flour, baking powder, baking soda and sugar.
Mix the wet and dry ingredients until well incorporated.
Stir in the Salted Caramel Sauce.
Pipe (or spoon carefully) the batter into the donut pan.
Bake for 8-10min and allow to cool slightly. Then transfer them to a wire rack and bake the remaining batter.