Add the apples, brown sugar, lemon zest and juice, flour, cinnamon, nutmeg, salt, and vanilla to a 9-inch square baking dish and toss together until well-combined.
3. Step
In a medium bowl, combine the oats, flour, cinnamon, brown sugar, and melted butter. Mix with your hands until the texture resembles a crumbly cookie dough.
4. Step
Scatter the crumble in clumps over the apples, then drizzle with the dulce de leche sauce.
5. Step
Bake the crisp for 20–25 minutes, or until the top is golden brown.
