Whisk together 1 cup of the half and half and the cocoa powder. Continue whisking together until ingredients are evenly mixed.
Add the remaining half and half, ancho (or other red chile peppers), cinnamon stick, cloves, sugar, and salt to the cocoa mixture. Bring to just below a boil. Reduce heat to very low, and let the mixture steep 30 minutes, stirring occasionally.
Strain the cocoa and half and half mixture into a mixing bowl. Add the melting chocolate wafers or pieces. Let them melt into the hot mixture, stir to hasten the process.
After thoroughly beating the eggs, add a ladle of hot chocolate mixture into the eggs, and beat again. Repeat 2 to 3 more times to slowly warm the eggs without cooking the yolks. Stir the tempered egg yolks into the remaining chocolate mixture.
Add back into the saucepan, and gently reheat to just below a boil. Stir constantly until the base thickens slightly. Allow mixture to cool to room temperature.
Stir in the vanilla and nutmeg. Chill completely. Stir in the chocolate chips/chunks.
Freeze according to manufacturer's instructions, or in a loaf pan in the freezer.
To serve - Scoop into bowls or cones. Garnish as desired.