Giant Garlic Knot

DoughStep 1Whisk together one ¼-oz. envelope instant dry yeast (2¼ tsp.), ¼ cup (50 g) sugar, 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, and 4 cups (500 g) all-purpose flour in a large bowl. Whisk 2 large eggs with 1 cup warm water in a small bowl to combine, then pour into dry ingredients. Add 10 Tbsp. unsalted butter, room temperature; mix with a sturdy rubber spatula or your hands until a shaggy dough forms, 6–8 minutes. Cover with a lid or plate; let sit 10 minutes (this will make it easier to knead).Step 2Turn dough out onto a lightly floured surface; knead, adding flour as needed to prevent sticking, until smooth and elastic, 8–12 minutes. Return dough to bowl and cover with plastic wrap. Let sit at room temperature until doubled in size, about 2 hours.Do Ahead: Dough can be made 1 day ahead. Let sit at room temperature 1 hour, then chill.Filling and AssemblyStep 3Set aside 2 garlic cloves from 1 head of garlic, cloves separated, peeled; place remaining cloves (about 10) in a food processor. Add 6 Tbsp. unsalted butter, room temperature, 1 tsp. garlic powder, 1 tsp. sugar, ½ tsp. crushed red pepper flakes, 6 oz. Parmesan, finely grated (about 3 cups), 1 cup (packed) parsley leaves with tender stems, and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt and process just until butter is smooth and parsley is finely chopped. (Or finely chop garlic and parsley with a chef’s knife, then mix with remaining ingredients in a small bowl.)Step 4Turn out dough onto a lightly floured surface. Using a rolling pin and dusting dough and surface as needed to prevent sticking, roll out dough to about a 20x14" rectangle with a short side facing you.Step 5Using an offset spatula, spread garlic butter evenly over dough. Cut in half lengthwise and roll each rectangle into a log, starting from a long side (like making cinnamon rolls; you should have two 20"-long logs). Using a serrated knife and long sawing motions, slice logs in half lengthwise, exposing insides. (If dough and butter feel very soft, chill logs 15 minutes before slicing.)Step 6Line up 2 of the strands of dough on a large piece of parchment paper so they are parallel to you with filling facing up, spacing slightly apart. Place remaining 2 strands over perpendicularly with filling facing up, spacing slightly apart. Weave strands to alternate under and over one another. Pick up a strand going under and lift over the strand next to it. Repeat with remaining under strand, working your way around counterclockwise until you reach where you started. Now work back around in the opposite direction (clockwise), placing under strands over again until you get back to where you started. Tuck ends underneath; pinch to adhere.Step 7Slide babka with parchment paper onto a large rimmed baking sheet. Cover loosely with plastic wrap and let sit until puffy (it may not quite double in size), about 1 hour, depending on ambient temperature. (To check if babka is ready for baking, remove plastic wrap and gently poke dough with a wet finger. If it springs back gradually with a shallow indent, it is ready.)Step 8Place a rack in middle of oven; preheat to 375°. Whisk 1 large egg, beaten to blend, and a large pinch of kosher salt in a small bowl. Using a pastry brush, gently brush babka with egg wash. Bake babka until golden brown, 35–40 minutes. (An instant-read thermometer inserted into the center should register 190°.)Step 9Just before babka is finished baking, finely grate reserved 2 garlic cloves into a small saucepan. Add 2 Tbsp. extra-virgin olive oil and a pinch of kosher salt and cook, stirring occasionally, just until oil is warm, about 2 minutes. Let cool; stir in 2 Tbsp. finely chopped parsley.Step 10Carefully slide babka onto a wire rack; brush with garlic oil. Top generously with more Parmesan. Serve with marinara sauce on the side for dipping.