• I recommend making the browned butter the day before you're ready to make the crumble. Once the butter is browned it will need to be cooled and refrigerated until it's chilled.
• If you have a nut allergy, you can leave out the pecans.

Brown the Butter

• Brown the butter the day before making the crumble or early in the morning if making the crumble in later in the evening. The butter is browned over low heat to reduce evaporation and avoid accidentally burning it. It will take about 20 minutes.
• Place 8 tablespoons (113 grams) of butter, cut into 8 pieces in a saucepan. Use a light-colored saucepan so you can see the milk solids as they brown. Place the saucepan over high heat. As soon as the butter starts to melt, reduce the heat to low. The heat is reduced to low to minimize evaporation and reduce the chance that you will burn the butter.
• As the butter melts, it will pop, and sizzle and the milk solids will begin to separate from the butter fat. Initially the milk solids will sit on top of the butter fat. As the butter continues to cook, the milk solids will start to drop to the bottom of the pan and turn brown.
• Once the amount of milk solid foam begins to lessen start to look for brown pieces on the bottom of the pan. Occasionally stir it so you can clearly see the bottom of the pan.
• The butter will change to a golden brown and the milk solids on the bottom of the pan will be brown. Watch the color of the milk solids - they should be a dark golden brown or russet color. If they are black, then you have burnt the butter and will need to start over. Don't use the burnt butter, it will give the crumble topping a bitter taste.
• Once the butter reaches the right color remove the pan from the heat and stir in the remaining 1-1/2 tablespoons of butter. Scrape the bottom of the pan to loosen the brown bits and pour the brown butter into a small bowl. Once the butter has cooled to about 80°F, refrigerate it until it's cold and solid, similar to cold butter used for making pie dough.

Make the Pecan Streusel Topping

• Cut the cold browned butter into 1/2-inch cubes and place it back in the refrigerator to stay cold while preparing the other ingredients.
• Place the flour, cinnamon, cardamom, and salt in a medium size bowl. Whisk until well combined. Add the butter to the dry ingredients and toss the butter into the flour mixture with your hands until all the butter is well coated.
• Use the pastry blender to cut the butter into the flour mixture, until the mixture resembles clumpy sand, some pieces small, some pieces the size of small lima beans. You can also you use your hands if you don’t have a pastry blender. To mix it with your hands take each piece of butter and smash it flat between your index finger and thumb. Continue to do this until the butter is broken up.
• Add the brown sugar and use your hands to rub the sugar into the butter-flour mixture. The mixture should be crumbly and look like large bread crumbs. Add the chopped pecans toss them into into the crumble. Refrigerate the crumble for 30 minutes or place it in the freezer for 15 minutes, while you prepare the apple filling.
• The crumble can be made up to one week in advance and refrigerated until ready to use.

Make the Apple Filling

• Preheat the oven to 350°F (180°C). Butter the baking dish.
• Taste the apples before adding the additional ingredients. The apples should be tart, but not so tart they cause you to pucker.
• Whisk together the granulated sugar, tapioca flour, cinnamon, and salt in a small bowl and set aside.
• Peel the apples. With the apples in the upright position and the stem pointing skyward, cut down and around the cores to remove the flesh in 4 lobes (you’ll be left with a square-shaped core). Set the lobes flat-side down and cut the apples into cut into 3/4-inch cubes.
• Place the apples in a large bowl. Add the lemon juice and use a silicone spatula to toss the ingredients together. Sprinkle the tapioca-sugar mixture over the apples and gently fold the dry ingredients into the apples until all the apples are coated. Taste the mixture. If the apple filing isn’t sweet enough add 2 more tablespoons of sugar and taste again.
• Spoon the apples into the prepared baking dish and use the back of the spoon to make an even layer. Spread the crumble over the apples. Leave the edges a little exposed so you can see the apple juices bubbling up as they crumble bakes.

Bake the Apple Crumble

• Bake the apple crumble for 40-60 minutes depending on how soft you want the apples in the center. If you want the apples in the center a little firm, bake the crumble for 40-45 minutes. If you want the apples soft all the way through bake the crumble for 50-60 minutes until you see the crumble topping in the middle starting to rise. In both cases, the apple juices should be rapidly bubbling around the edges of the baking dish. The syrup will be thick and shiny.
• Remove the crumble from the oven, set it on a wire rack to cool at least 20 minutes to allow the juices to set up. It will still be warm.
• Serve it plain, or with vanilla ice cream with some of the juices from the pan spooned over the top.

Storage

• The crumble can be stored at room temperature for up to 2 days unless it's warm in your house (over 75°F). In that case, I recommend storing it in the refrigerator after 1 day at room temperature, covered with plastic wrap. The crumble is good in the refrigerator for up to 3-4 days.
• To store the crumble in the refrigerator let it cool completely before covering tightly with plastic wrap or foil.