Preheat your oven to 375°F (190°C) and position a rack in the center for even baking.

Open the cans of sliced peaches and drain them well. Grease an 8x8 inch baking dish with butter. Layer the peaches in the dish.

Combine the drained peaches with 1/4 cup of brown sugar and 1/4 teaspoon of cinnamon. Add diced butter and half of the vanilla extract. Mix gently.

In another bowl, stir together the oats, remaining 1/4 cup of brown sugar, 1/4 teaspoon of cinnamon, and a pinch of salt.

In a separate bowl, whisk together the reserved peach juice, heavy cream, and beaten eggs. Pour into the bowl with the oat mixture and fold until well combined.

Spoon the oat mixture evenly over the peaches, dot with remaining butter, and garnish with reserved peach slices.

Bake for 45 minutes until the top is golden brown and the oatmeal has set firmly.

Remove from the oven and cool for 15 minutes before serving warm.