In a microwave safe measuring cup, heat the milk to 100°F / 38°C. Whisk in the yeast and the sugar. Set aside until the mixture begins to foam. (~5 minutes)
While waiting, add the flour, salt, egg, and butter to the bowl of a stand mixer fitted with the dough hook attachment. When the yeast mixture begins to foam, add it in to the rest of the ingredients.
Knead the mixture on medium-high speed for ~10-20 minutes. The dough is ready when it is no longer sticking to the sides or bottom of the bowl, and passes the windowpane test.*
Once the dough is done kneading, shape the dough into a ball and place it back into the mixing bowl. Cover the mixing bowl with plastic wrap, and place it in a warm area to rise until doubled in size (~1 hr.)**
Once the dough has doubled in size (or after taking it out of the fridge after rising overnight), lightly punch it down to remove excess air.
Butter an 8" cake pan, and get out a sheet of parchment paper. Crinkle up the parchment paper, then un-crinkle it and place it in your buttered pan, pressing the parchment up the sides of the pan. This will give you a way to easily lift the cake out of the pan after it's done baking.
Use your hands to push the dough down into the pan so that the dough is an 8" circle on the bottom of the pan. If the dough keeps snapping back, leave it to rest for 5 minutes before trying again. Cover the dough with plastic wrap or a towel and leave to rise at room temperature until doubled in size (~30-45 min.)
Once the dough has almost completely doubled in size, start with your topping and preheat the oven to 350°F / 175°C.