In a large bowl, mix together white sugar, warm water, and active dry yeast. Allow the mixture to sit for 5 minutes until it starts to foam.
Add all-purpose flour, ½ cup of sugar and kosher salt to the bowl and knead for about 10 minutes until it forms a soft dough.
Grease a large bowl with vegetable oil and place the dough in it. Cover with a damp cloth and let it rise for about an hour.
Preheat the oven to 375°F. Grease a baking sheet with cooking spray and spread the dough onto it. In a large pot, bring 4 cups of water to a boil and add baking soda to it.
Take one pretzel at a time and dunk it in the lye bath for about 30 seconds. Place the pretzels on the baking sheet after dunking them.
Brush melted butter over each pretzel and sprinkle some Maldon flaky sea salt. Bake the pretzels for 20-25 minutes until the surface turns golden brown. Allow them to cool down before serving.