Preheat the oven to 350°F (175°C). In a mixing bowl, cream together the softened butter and sugar until light and fluffy. Stir in the vanilla extract.

Gradually add the flour and salt, mixing until just combined. Press the mixture into the bottom of a greased 9x13 inch baking pan.

In a separate bowl, combine the sliced peaches, sugar, lemon juice, cornstarch, and cinnamon. Toss until the peaches are well coated.

Spread the peach filling evenly over the crust in the baking pan.

In a bowl, mix together the oats, brown sugar, flour, melted butter, and salt until crumbly. Sprinkle the topping evenly over the peach filling.

Bake in the preheated oven for 30-35 minutes, or until the topping is golden brown and the filling is bubbly.

Allow to cool completely before slicing into bars.