The core recipe is:

• 2 cups flour
• 1 tsp salt
• 4 large eggs
• up to 2/3 cup milk

Depending on the size of the eggs, you may need more milk. Start with 1/2 cup.

If batter gets too liquid, add a little flour.

Making homemade spaetzle is surprisingly faster and easier than making store-bought dried spaetzle. All you have to do is mix a simple batter of flour, eggs, milk, and salt and use the spaetzle utensil of your choice to drop the batter into boiling water. Another great thing about spaetzle is that it cooks in about 2 minutes.

Culturally, spaetzle—also spelled spätzle—is associated with Swabia, a region of southwest Germany. You'll find spaetzle and spaetzle-type dumplings in the cuisines of southern Germany, Austria, Slovenia, Hungary, Alsace, Moselle, and South Tyrol.

Spruce Eats https://www.thespruceeats.com/german-spaetzle-recipe-5206113

Käsespätzle

Cheese spaetzle are just served with melted cheese, often heated up and broiled spaetzle that are made ahead of time.