In a small bowl mix the flour, sugar, baking powder, salt, cinnamon and nutmeg.
Place the bread in a large bowl and add/pour in the half and half or milk; toss gently to combine with a spoon; let stand until the bread is very soft and is beginning to fall apart, stirring the mixture occasionally (this should take about 8-10 minutes).
Add the flour/cinnamon mixture to the softened bread mixture; mix to blend.
In a small bowl whisk together eggs, 3 tablespoons melted butter and vanilla; add to the bread mixture, then let stand for 15 minutes.
Set oven to 250°.
Prepare a baking sheet.
Melt butter in a heavy skillet (use as much as desired) over medium heat.
Drop batter by about 1/4 cup into skillet.
Cook the pancakes until bubbles form on the surface and the bottoms are brown (about 2 minutes).
Using a spatula carefully turn the pancakes over and cook for about 2 minutes longer.
Transfer the pancakes to the baking sheet and keep warm in the oven.
Repeat with any remaining batter adding in more butter as needed.