Preheat the oven to 350°F (175°C)
Line a large baking sheet with parchment paper and set aside
Press the two pie crusts together to form a ball on a clean surface
Roll the dough into a 12-inch circle and transfer it to the prepared baking sheet
Toss the apple slices with granulated sugar, 3 tbsp flour, and 1 tsp cinnamon in a large bowl
Spread the apple mixture evenly onto the center of the pie dough, leaving a 2-inch border
Fold the edges of the crust up over the apples, working your way around the circle
Slide the galette onto a rimmed baking sheet
In a small bowl, mix the topping ingredients with a fork until crumbly
Sprinkle the topping evenly over the apples in the center
Bake for 40-50 minutes, until the apples are tender and the crust is golden brown
Remove from the oven and cool for at least 10 minutes before serving
Drizzle with caramel sauce and serve with ice cream or whipped cream if desired