Begin by bringing a pot of water to a gentle boil. Score the peaches with an 'X' on the bottom and carefully drop them into the boiling water for about 30 seconds. This blanching will make peeling easy. Remove the peaches and immediately place them in a bowl of ice water for a few minutes. Once cooled, peel the skin off and slice the peaches into ¼-inch thick pieces.

While the peaches are cooling, hull and halve or quarter the strawberries, depending on their size. Set the prepared strawberries aside in a separate bowl.

In a large mixing bowl, gently combine the sliced peaches and prepared strawberries. Use a spatula to toss the fruit together.

Sprinkle the granulated sugar, flour, ground cinnamon, and nutmeg over the fruit mixture. Lightly fold the dry ingredients into the fruit.

Drizzle the lemon juice over the fruit mixture, gently toss until well coated.

In a separate bowl, whisk together the remaining flour, rolled oats, packed brown sugar, baking powder, and salt.

Take the cold, cubed butter and add it to the bowl with the dry topping mixture. Incorporate the butter until the mixture resembles coarse crumbs.

If using chopped pecans or walnuts, stir them into the topping mixture now.

Preheat your oven to 375°F (190°C).

Lightly grease a 9x13 inch baking dish with butter or cooking spray.

Spread the fruit filling evenly across the bottom of the greased baking dish. Sprinkle the prepared topping mixture over the fruit.

Place the baking dish in the preheated oven and bake for 35–45 minutes.

Once baked, remove your crisp from the oven and let it cool for about 10–15 minutes.

Spoon generous portions of your warm Peach Strawberry Crisp into bowls. Optionally serve with a scoop of vanilla ice cream or a dollop of whipped cream.