Sprinkle the yeast over warm water in the bowl of your stand mixer. Let proof for 5 minutes, until foamy/creamy.
Turn the mixer to low and add the milk, melted butter, 2 eggs, sugar, and salt until mixed thoroughly.
Add the flour in two batches and mix only until just combined. The dough will be wet and sticky.
Cover with plastic wrap and let rest for 2 hours, until dough has doubled.
Punch down and refrigerate covered overnight or for at least 4 hours.
Divide dough into 70 gr balls and set on a lined baking sheet.
Cover and let rest for 15 minutes.
Flatten each dough ball and top with a couple slices of jalapeno and pinch of grated cheddar and place the sausage on top.
Wrap the dough around the fillings, pinching the edges together and placing seam-side down on the baking sheet.
Cover and let rest for 20 minutes, while preheating oven to 180°C.
Bake for 25-30 minutes, until browned.
Let the kolache cool for 20 minutes and serve.