Sourdough Chocolate Soft Pretzels with Chocolate Ganache Dipping Sauce

In the bowl of a stand mixer, combine the sourdough starter, warm water, brown sugar, bread flour, Dutch-process cocoa powder, espresso powder (if using), and salt.
Using the dough hook attachment, mix on low speed until the dough comes together. As the mixer continues running, add the softened butter one tablespoon at a time, allowing each addition to fully incorporate before adding the next.
Continue kneading on medium speed for several minutes, then increase the mixer to high speed and continue kneading for a total of 7–10 minutes, or until the dough is smooth, elastic, and no longer sticking to the sides of the bowl.
No stand mixer? Mix everything together in a large bowl, then knead by hand for 10–12 minutes, gradually working the softened butter into the dough until fully incorporated.

The dough should feel soft and smooth. It should be slightly tacky but not overly sticky. It should pull cleanly away from the sides of the mixing bowl.

Lightly grease a medium bowl with oil and place the dough inside.
Cover with greased plastic wrap or a damp kitchen towel and let rise at room temperature for 4–8 hours, or until the dough has increased in size by about 50% or nearly doubled.

Cover the bowl and refrigerate the dough for 8–24 hours.
This overnight fermentation develops a richer flavor while making the dough much easier to shape.

The following day:
Line two large baking sheets with parchment paper. Then cut 8 individual parchment squares. Each pretzel will be laid on them--it makes for easier transport to the baking soda bath.
Remove the dough from the refrigerator.
Divide into 8 equal pieces (about 110 g each).
Working with one piece at a time:
Roll the dough into a rope about 20–24 inches long.
Form the rope into a large "U."
Cross the ends over one another twice.
Fold the twisted ends down toward the bottom of the "U" and gently press to seal.
Arrange the shaped pretzels on their individual parchment squares on the prepared baking sheet.
Helpful Tip: If the dough becomes warm or sticky while shaping, place it back in the refrigerator for 10–15 minutes. Cold dough is much easier to work with.

Cover the pretzels loosely with greased plastic wrap and allow them to rise for 1–3 hours, or until noticeably puffy.
Meanwhile, preheat the oven to 425°F (220°C).

In a large pot, combine the water, baking soda, and brown sugar. Bring the mixture to a gentle boil over medium-high heat.

Working with 2–3 pretzels at a time, carefully lower each pretzel into the baking soda bath. You can keep the parchment paper square with the pretzel, if needed, then use tongs to carefully remove them from the bath.
Boil for 30–40 seconds per side, then remove with a slotted spoon or spider strainer and transfer back to the parchment-lined baking sheet.

Whisk together the egg and milk until smooth. Brush each pretzel generously with the egg wash.

Bake for 15–20 minutes, or until the pretzels are puffed and baked through.
Because of the cocoa powder, these pretzels won't develop the same deep golden color as traditional pretzels, so rely more on their texture than their color to determine doneness. The internal temperature should be 200°F (93°C).
Allow the pretzels to cool for about 10 minutes before adding the chocolate drizzle.

Microwave Method: Place the milk chocolate melting wafers in a microwave-safe bowl. Microwave in 30-second intervals, stirring after each interval, until melted and smooth.
Double Boiler Method: Fill a small saucepan with about 1 inch of water and bring it to a gentle simmer. Place a heatproof bowl over the saucepan, making sure the bottom of the bowl doesn't touch the water. Add the chocolate melting wafers and stir occasionally until completely melted and smooth.
Drizzle the melted chocolate over the cooled pretzels. Sprinkle with coarse salt (optional)

In a microwave-safe bowl, combine the heavy cream and butter. Microwave for 1½–2 minutes, or until the cream is steaming and the butter has melted. Add the chocolate and let it sit for 2 minutes before whisking until smooth and glossy. If needed, microwave for an additional 10–15 seconds and whisk again until silky smooth. Serve immediately alongside the warm pretzels for dipping.