Mix flour, basil, parsley, garlic salt, and pepper together in a large bowl, and make a well in the center of the mixture.

Whisk eggs and 1 cup water together in a medium bowl. Pour into the well in the flour. Stir until well combined; spaetzle dough will be thick and sticky.

Bring remaining 4 cups water to a boil in a pot over high heat; add salt.

Meanwhile, place spaetzle dough onto a cutting board. Slice off tiny dollops of dough, about the size of a pretzel stick, using a sharp knife. Drop into boiling water and cook until they float to the top of the pot, 1 to 2 minutes. Transfer dollops to a bowl using a slotted spoon. Set aside.

Melt butter in a large frying pan over medium-high heat. Add brown sugar, garlic, and cayenne and stir until sugar is melted, about 1 minute. Add kielbasa and cooked spaetzle to butter mixture; stir over medium-high heat until kielbasa is warmed, 4 to 5 minutes.