Preheat oven to 350 degrees.

Prepare crispy topping separately from peaches. Mix together oats, flour, cinnamon, salt, and brown sugar until they are well-combined.

Using a pastry cutter, mix butter into flour and oat mixture. Make sure your butter is cold. Continue to cut butter into mixture until the texture resembles small peas.

Place oat mixture onto a lined baking sheet and spread onto baking sheet in an even layer. Allow to bake for approximately 20-25 minutes or until golden brown.

While crispy topping is baking, prepare peach mixture. Add peaches, cinnamon, vanilla extract, lemon juice, and brown sugar into a large sauce pan. Turn fire on medium and allow peaches to cook down. Toss gently every few minutes for even cooking. Cook about 10-15 minutes, and then cover with lid, turn off the fire, and allow peaches to sit for at least 10 minutes. This will prevent the peaches from overcooking.

Check on crispy topping in the oven. If baking is uneven, break the crust into smaller pieces and rotate around the pan. Place back into the oven, rotating to ensure even baking.

When crispy topping is done, remove from oven and allow to cool.

When ready to serve, scoop a spoonful of simmered peaches and top with crispy oat topping, and serve with ice cream or whipped cream.