Leave the bread out overnight uncovered to make it stale and firm. Mix the half and half, maple or sugar, vanilla, cinnamon, candy cap powder and salt and puree until smooth in a blender.
Whisk in the egg yolks to the cream-mushroom mixture and pass through a strainer to ensure it’s smooth. Mix the bread cubes with the custard mixture thoroughly in a bowl, then allow to stand overnight, if possible, gently stirring the mixture every 4-5 hours or so to ensure even distribution of the custard.
To cook the pudding, generously grease a bread loaf pan or terrine mold and add the bread mixture. Place the pan in a water bath, and cook, covered, for 1.25 hours at 250 degrees, or until hot throughout and slightly risen.
Remove the pudding from the water bath, allow to cool almost to room temperature, then wrap with astic wrap and place a weight on top of the pudding (optional).
The easiest way to press it, is to take another pan the same size as the one the pudding was cooked in and place it on top, placing a brick or something similar in weight on top of that, wrapped in foil. Allow the pudding to sit overnight, then remove the weights the next day.
To serve the pudding, slice into 1.5-2inch pieces, heat the slices in the oven at 325 or so until hot throughout, then top with a scoop of vanilla ice cream and the candy cap caramel sauce and serve.
If money is an issue, you don't have to use candy caps in the bread pudding. It's perfectly fine to anoint it with warm candy cap caramel sauce afterwords.
I'm using a restaurant terrine mold here since I like nice slices, but you can use whatever dish works that you have on hand.
1/2 cup dried golden raisins can be warmed in a little brandy and mixed in before baking.