Remove your pie dough from the freezer to thaw if needed. While it thaws, prepare the crumble topping by combining the flour, sugar, brown sugar, and salt in a bowl. Pour the melted butter over the dry mixture and stir with a fork until the mixture resembles coarse breadcrumbs with some pea-sized clumps remaining. Transfer the crumble to the refrigerator to chill while you work on other components. I prefer using Kerrygold butter here because its rich, cultured flavor really shines through in the topping.

In a large skillet over medium heat, add the lemon zest and lemon juice, letting them warm for about 30 seconds. While the lemon heats, peel, core, and slice all 5 pounds of apples into quarter-inch thick slices, working quickly to prevent oxidation. Add the sliced apples to the skillet and toss to coat with the lemon. Sprinkle in the brown sugar, sugar, flour, salt, cinnamon, nutmeg, and cardamom, stirring gently to combine everything evenly. Cover the skillet and cook on medium heat for about 20 minutes, stirring frequently, until the apples are tender but still hold their shape. Remove from heat and stir in the vanilla extract. Spread the filling onto a sheet pan and refrigerate for at least 2 hours (or freeze for 30 minutes) to cool completely and allow the flavors to meld.

Roll out the thawed pie dough on a lightly floured surface until it’s about an eighth-inch thick and large enough to fit your 9-inch pie dish with a slight overhang. Carefully transfer the dough to the pie dish, gently pressing it into the bottom and sides without stretching. Trim any excess dough and crimp the edges decoratively if desired. Place the lined pie dish in the refrigerator for 30 minutes to chill and relax the gluten, which will help prevent shrinking during baking.

Preheat your oven to 425°F and place a baking sheet on the lowest rack to catch any drips. Remove the chilled pie crust from the refrigerator and add the cooled apple filling from Step 2, spreading it evenly. Remove the crumble topping from the refrigerator and sprinkle 1 to 2 cups of it over the apples, leaving about 1 cup reserved for later. The first application won’t cover the filling completely, which is intentional. Place the pie on the middle rack and bake at 425°F for 15 minutes until the crust begins to set.

After the initial 15 minutes, reduce the oven temperature to 350°F and bake for an additional 10 minutes. This temperature drop prevents the crumble from browning too quickly while the filling finishes cooking through.

Remove the pie from the oven and carefully spread the reserved crumble from Step 1 over the areas where the apples are still visible, creating an even, complete topping. Cover the pie’s crust edge with foil to prevent over-browning, then return it to the 350°F oven and bake for 25 to 35 minutes more, until the crumble is golden brown and the filling bubbles slightly at the edges. I like to remove the foil for the last 5-10 minutes of baking if I want an extra-golden, crunchy top—just keep an eye on it to make sure the crust doesn’t burn.

Remove the pie from the oven and transfer it to a wire cooling rack. Allow it to cool for at least 4 hours before slicing—this resting period lets the filling set properly so it slices cleanly without running. Serve at room temperature or slightly warm, optionally with vanilla ice cream or whipped cream.