This apple babka features a filling of apples cooked in honey and boiled apple cider for a burst of rich apple flavor, and the apple cinnamon glaze is the perfect finish. Apple honey babka is what to serve for an Autumn breakfast, brunch, or after your festive Rosh Hashanah (Jewish New Year) meal!Adapted from King Arthur Baking and Jamie Geller
Prepare the dough: Heat the milk until it’s warm to the touch, about 100 °F to 110 °F as read on a digital thermometer. Stir in the sugar, then sprinkle the yeast over the milk and set aside to proof for about 5 minutes or until bubbles form on the surface of the milk.
Pour the milk into the bowl of a stand mixer fitted with the paddle attachment. Add the egg, honey, and vanilla, then mix on low speed for about 30 seconds. Add the flour and the salt and mix on low speed until a sticky dough forms. Add the butter, 1 tablespoon at a time, and mix in thoroughly before adding in another tablespoon.
When all the butter is incorporated, switch to the dough hook and knead the dough on medium speed until a smooth and slightly sticky dough forms, about 5 to 10 minutes. Add more flour in 1 tablespoon increments as needed to make the dough the right consistency. Gather the dough into a ball, stretching it so the top of the ball is smooth.
Spray a 2-quart dough rising bucket or a large bowl with canola oil spray and place the dough ball in smooth side down to wipe it with oil. Turn the dough with the gathered rough part of the dough down and the smooth surface of the ball facing up. Cover with the lid or plastic wrap and let it rise in a warm place for about 1 hour, or until the dough has doubled in size. The inside of an unheated oven with the light on works well.
Make the apple filling: Peel and core the apples, then slice the apples thinly, about ⅛-inch thick. See the Recipe Notes for tips on the best way to do this step. Cut the sliced apples into small pieces.
Melt the butter in a large skillet over medium-high heat. Cook the apples, stirring occasionally, until they start to soften, about 5 to 10 minutes depending on the thickness of the slices.
Add the honey, boiled apple cider, and cinnamon to the cooked apples. Reduce the heat and simmer until the sauce has thickened, about 8 to 10 minutes. Transfer to a bowl and allow the apples to cool to room temperature, about 30 minutes.
Assemble the babka: Spray a standard loaf pan with baking spray and line with parchment paper, leaving a 2-inch overhand on the long sides. Set aside.
Dust a clean surface with flour and roll the dough out to a rectangle roughly 10- x 14-inches, about ¼-inch thick, with a long side facing you (landscape orientation).
Using a large offset spatula, spread the cooled apples over the surface of the dough, leaving a 1-inch strip bare along the long side away from you. Tightly roll the dough up from the long side facing you, making a 14-inch rope. Try to catch as much of the filling as possible as you roll so it will be evenly distributed in the babka.
Slice the rope in half lengthwise using a bench scraper, making two 14-inch long pieces. If you want, you can twist each long piece individually so the apples are trapped inside the dough, tucking in any apples that may have fallen out.
Wrap the two lengths of dough together into a rope. Squish the twisted dough together and transfer it to the prepared loaf pan, tucking in any stray pieces of apples and dough. This is messy business but worth it in the end!
Cover the pan with a shower cap or a piece of greased plastic wrap and let the dough rest for 30 minutes.
Bake the babka: While the babka loaf is resting, preheat the oven to 350 °F.
Whisk together the beaten egg with the water to make an egg wash. Once the dough has rested (it won’t have risen much, just a tiny bit), brush the egg wash onto the top of the dough with a pastry brush.
Place the loaf pan on a quarter sheet baking pan (to catch any drips) and bake for 45 minutes. Cover the top with foil after about 30 minutes if it's getting too dark.
Reduce the oven temperature to 325 °F and continue to bake until the top of the babka is deep brown, about 15 minutes more, and the loaf sounds hollow when tapped on the top. The babka will be fully baked when the center reads at least 190 °F.
Let babka cool in the pan for 15 minutes on a wire cooling rack, then use the parchment paper to lift the babka out of the pan and transfer it to back to the wire cooling rack. Let cool completely.
Make the apple glaze: In a medium bowl, whisk together the powdered sugar, cinnamon, and salt.
Add the boiled cider and 1 teaspoon of milk into the powdered sugar mixture and stir until smooth. The mixture will be thick, but should still drizzle from a spoon (like the consistency of molasses). Adjust the glaze's consistency with additional milk (if it's too thick) or powdered sugar (if it's too thin) in ½ teaspoon increments as needed.
The glaze will resist drying at room temperature if it’s too loose, so it's best to drizzle a bit on a plate or wax paper and see if it sets after about 10 minutes or so. If it doesn't dry, add in a little more powdered sugar to the icing.
Place the glaze in a disposable pastry bag and snip a small opening at the bottom (or use a small ziplock bag and snip the corner). Drizzle the glaze over the babka, letting it set for about 10 minutes. Serve & enjoy!
Storage instructions: The unglazed babka will keep well wrapped or in an airtight container for 3 to 4 days. You an also slice it thickly and use it for Apple French Toast. Delicious!
Make-ahead instructions: The filling and glaze can be made up to 5 days ahead, covered tightly and stored in the refrigerator. Bring them to room temperature before using.
Try to find apples that will hold their shape while baking. Several examples include Granny Smith (a classic, but a bit tart in this application, if you ask me), Paula Reds (crisp and sweet, and won’t discolor after being cut), or Jazz (these work quite well). Other suggestions would be Pink Lady, Jonagold, or Golden Delicious. Feel free to combine apple varieties as well.Boiled apple cider is just apple cider that's been boiled down until it's got the same consistency as honey. It's easy to make, or you can find ready-made boiled cider. In a pinch, you can use thawed apple juice concentrate, but it will be more liquidy and less flavorful than the boiled cider.Tips on preparing the apples: If you have an apple peeler/corer/slicer, you can prep the apples in a single step. Otherwise, a serrated peeler will make quick work of peeling the apples, and a melon baller is a good way to scoop out the core. Using a mandolin slicer speeds up the slicing and insures uniform pieces. Just be careful with the sharp blade, and make sure you use the food guard!If you’d rather not make the apple glaze, you can just sprinkle some course sugar on the egg-washed babka before putting it in the oven to add sweetness and crunch (but really…no glaze?).