Preheat your oven to 350°F (175°C). Butter an 8x8-inch baking dish to prevent sticking and ensure a golden crust on the edges. Set the dish aside while you prepare the filling and topping.

In a medium bowl, combine the 3/4 cup white sugar, 1/2 cup all-purpose flour, and a pinch of kosher salt. Add the remaining softened, cubed unsalted butter. Using the back of a fork, work the butter into the dry ingredients until the mixture resembles coarse crumbs. Set aside for topping the apples. I find that fully softened butter makes the topping extra crumbly and delicious.

Peel and thinly slice the Granny Smith apples, then layer them evenly in the prepared baking dish. In a small bowl or cup, mix together the 1/4 cup water and 2 teaspoons vanilla extract. Pour this mixture evenly over the apples. Sprinkle the 1 teaspoon ground cinnamon and 1/2 teaspoon ground nutmeg evenly over the top of the apples for a warm, aromatic flavor. For more depth of flavor, I sometimes mix the spices directly with the apples before layering.

Sprinkle the prepared butter-flour crumble topping (from Step 2) evenly over the apple mixture in the baking dish. Place the dish in the preheated oven and bake for about 50 minutes, or until the top is golden brown and the apples are bubbling at the edges. The aroma should be wonderful as it bakes!

Remove the apple crisp from the oven and allow it to rest for at least 5 minutes before serving. This helps the juices thicken and makes it easier to serve. For an extra treat, I love to top warm apple crisp with a scoop of vanilla ice cream or a dollop of whipped cream.