This king cake has something for everyone. It combines sweet, salty, spice, crunch, caramel and cinnamon all in one delicious dessert.
For the cake:
Assemble the dough the evening before baking. Combine flour, salt, sugar and cinnamon in the bowl of a mixer fitted with a dough hook attachment. Warm the milk gently to just above room temperature and combine with the yeast; set aside until foamy (about 5 minutes).
Add butter to mixer and mix on low until all the butter is coated in flour and has rough, pebble-like texture. Stream in the yeast-milk mixture and the egg yolks.
Raise the speed to medium and mix until the dough is smooth and shiny and coming away from the sides of the bowl (about 5 minutes). You may need to scrape down the sides of the bowl a few times.
Shape your dough into a ball, place in a lightly oiled bowl, cover with plastic wrap and refrigerate overnight.
For the filling:
Melt the butter gently. Whisk in sugar, cinnamon and gingersnap crumbs. Allow to cool slightly.
For the dough:
The next day, remove dough from refrigerator. Roll the chilled dough into a large, thin rectangle, about 14 inches long and 20 inches wide. Spread your slightly warm, soft filling evenly all the way to the edges of the rectangle.
Beginning at the bottom, roll the dough into a tight cylinder (as if you were assembling cinnamon rolls). If the dough starts to warm up or to become sticky or unmanageable, chill for a few minutes until firm.
Making sure the seam of your dough roll is facing down, use a sharp knife and slice the dough in half lengthwise, starting two inches from the top. You will now have two long lengths of dough. Starting at the end that remains connected, begin to "braid" the dough, wrapping it gently but tightly around itself. Your layers may begin to fall open a bit at this point; but that's OK — you're going for a rustic appearance.
Loop the dough into an oval and pinch the ends together. Place on a parchment paper lined sheet tray. Spray with nonstick cooking spray, cover loosely with plastic wrap and allow to proof for about an hour and a half to two hours, or until doubled in size.
For the soaking syrup:
Combine water, sugar, butter and cinnamon stick and simmer until sugar is dissolved and butter is melted. Set aside to cool.
For the salted caramel:
Combine water, sugar and lemon juice in the bottom of a heavy, non-reactive pot. Cover and place over medium-high heat. After a few minutes, check your caramel; if you see any crystals forming around the edge, brush them down with a little water and re-cover.
Once the caramel begins to turn a light amber, take the lid off and swirl the pot gently to ensure the caramel cooks evenly. When the caramel turns a dark amber, or resembles the color of a penny, when a little is dropped on a white plate, shut off the heat and carefully whisk in the cream and salt.
Allow to cool about fifteen minutes before using.
For the streusel:
Preheat oven to 350°F. Combine the flour, both sugars, salt and spices in a bowl. Sprinkle the vanilla over the mixture. Cut in the butter using your fingers or a food processor until the mixture has a sandy texture and looks like little coarse pebbles. Place in the refrigerator and chill until quite cold.
Once chilled, spread your streusel onto a sheet tray lined with parchment paper and bake for 10–15 minutes, stirring often, until the streusel is an even golden brown.
Preheat your oven to 400°F.
Once your king cake has proofed, place it into your oven and immediately drop the temperature to 350°F. Bake for 40–45 minutes or until your king cake is an even, dark golden-brown. Rotate your tray halfway through the cooking time.
For the assembly:
Allow your king cake to cool for ten minutes and brush gently with your cinnamon soaking syrup. After cake has cooled completely, drizzle it with the salted caramel glaze and top it with the spiced streusel.