Preheat the oven to 325° F. Grease an 8 x 8 baking dish with nonstick spray and set aside.: You will smell a faint warmth as the oven comes to temperature, which helps the custard start cooking evenly when it goes in. Preheating ensures the edges set at the same rate as the center, preventing an undercooked middle and overbrowned rim. If the oven is not fully preheated the bake time can extend significantly, so always wait until the temperature stabilizes. A common mistake is placing the dish in an oven that is still warming, which leads to uneven texture and longer baking time.
Cut your bread into 1-inch cubes and place them in the prepared baking dish.: The cubes should be uniform so each piece soaks up custard consistently, creating a pleasing mosaic of texture. As you cut the bread you will notice the crumb density, and slightly stale slices will produce the best structure. Crowding the dish can prevent liquid from penetrating all pieces, so arrange cubes in a single even layer rather than tightly packed clumps.
Meanwhile, in a large bowl, combine the coconut milk, eggs, applesauce, cardamom, cinnamon, and nutmeg. Beat the mixture with a whisk until everything is well combined.: The aroma of cardamom and cinnamon will become noticeable as you whisk, and the mixture should look homogenous and slightly glossy. This step is crucial to distribute spice and ensure the custard sets uniformly. Overwhisking can incorporate too much air, creating bubbles that alter the texture, so whisk just until smooth.
Fold the apples into the mixture before pouring the contents over the bread cubes. Press the cubes down into the mixture to make sure each one soaks up the liquid.: You will hear a gentle plop as apple pieces sink, and visually you should see the custard fill gaps between cubes. Pressing ensures the bread absorbs evenly, which is why I press down with the back of a spoon or my hands covered in plastic wrap. Not pressing enough can leave dry pockets, while pressing too hard can crush the cubes and result in a denser set.
Bake for 45 minutes, until the pudding is set and no longer jiggles when you shake the pan. You can also insert a knife into the middle of the pudding to make sure it comes out clean.: During baking the surface will turn a light golden color and the scent of spices will intensify. Listen for a faint bubbling sound at the edges as the custard comes to set. The center should feel firm when nudged and a skewer should come out mostly clean, perhaps with a few moist crumbs. Baking too little leaves a runny center, while baking too long dries the custard and makes the texture rubbery.
Allow the pan to cool on a baking rack for at least 15 minutes before slicing.: Cooling lets the custard finish setting and makes for neater slices. You will notice steam easing away and the aroma will mellow. Cutting immediately can cause the pudding to break apart, so patience yields cleaner presentation. A mistake people make is slicing while piping hot, which leads to a loose, soupy interior.
This pudding can be served hot or cold. Store it in the refrigerator (covered) for up to two days.: When served warm you will experience the fullest aroma and a tender, creamy mouthfeel. Chilled slices are firmer and great for packing or preparing ahead. Refrigeration stabilizes the custard but can dull some of the spice perfume, so I briefly reheat slices if I want that freshly baked scent. Be careful not to overheat in the microwave which might make the custard rubbery.