This is my favorite savory muffin. I usually bake a dozen of these and stash them in the freezer. They make a wonderful breakfast or afternoon snack. All I have to do is to take them out of the freezer and zap them in the microwave, make a cup of tea, and breakfast is served.
The exterior will be golden brown and crunchy while the center will be soft and chewy. You can also make this as a loaf and slice it or you can spread it in a pan and cut it into bars.
Place the oven rack in the middle of the oven and preheat the oven to 375 degrees.
In a bowl, proof the yeast: Mix the yeast with the sugar and warm water and wait until it foams and bubbles. In another bowl, mix the powdered milk with the flour. Add the olive oil and rub it into the flour mix until the flour absorbs the oil and resembles wet sand.
Add the egg, then the vinegar (you can also beat the egg with the vinegar and then add it to the flour). Add the oregano and cheese. Add the proofed yeast and stir with a spatula or wooden spoon (the dough will be really sticky — resist the temptation to add flour). Lightly coat a muffin pan with oil, then sprinkle it with flour.
Using 2 tablespoons, drop the mix into the muffin pan. Bake until the rims start to turn golden brown, about 30-40 minutes. Place under the broiler until the tops are golden brown. Allow it to cool for 2-4 minutes, then remove from the pan and cool on a wire rack.