Whisk together the flour, malt syrup, yeast, and salt in the bowl of a stand mixer. Add the lukewarm water, then fit the mixer with a dough hook and mix for 8 to 10 minutes, or until the dough is smooth and shiny. Coat a large bow with nonstick cooking spray, transfer the dough to the bowl, and mist the top of the dough with nonstick cooking spray. Cover with plastic wrap; let sit in warm place until doubled in size (1 to 1 ½ hours).

Line a baking sheet with parchment paper; coat with nonstick cooking spray. On a clean work surface coated with nonstick cooking spray, roll the dough into a 12-inch-long log; cut into six equal portions. Shape each portion into a small round and place on the prepared baking sheet. Cover with plastic wrap; let rest 10 minutes.

Roll and stretch each portion into an 18- to 20-inch rope, leaving the middle thicker. Form into a U shape; cross the ends twice, leaving the remaining ends 3 inched long. Press the ends into base of U shape. Return the shaped dough to the baking sheet. Wrap with plastic wrap; freeze 2 hours to 1 week.

Before baking, make sure the pretzels are frozen solid. Bring 2 cups of water to a boil and pour into a heatproof bowl just large enough to hold one pretzel. Add the baking soda and stir until the soda dissolves. Let the mixture come to room temperature. One at a time, dip each frozen pretzel into the baking soda mixture for 5 seconds, then turn and soak for 5 seconds more. Lift out the pretzel and let the excess water drip back into the bowl. Return the pretzels to the baking sheet. Cover loosely with plastic wrap coated with nonstick cooking spray; rest in warm place for 1 to 2 hours, until puffy.

Preheat the oven to 400°F. Brush the egg wash on the pretzels. Sprinkle with kosher salt. Bake for 25 to 30 minutes, until deep golden brown. Remove from the oven and let cool on racks.