Using a Ninja Woodfire Oven:
Evenly cover the bottom and sides of a 2 ½ quart baking dish with butter. Shingle the bread in the pan and place 1 cup of blueberries in between the slices.
In a medium bowl, whisk together milk, cream, eggs, cinnamon, nutmeg, vanilla, and 1 teaspoon salt until combined and smooth. Evenly pour the mixture over the bread. Gently press the bread down to absorb the liquid. Cover the baking dish with plastic wrap and place in refrigerator overnight.
In a medium bowl, combine the mascarpone, ricotta, lemon zest, and ½ teaspoon salt. Transfer mixture to piping bag or large zip-top bag and place in refrigerator overnight.
Install the Accessory Frame in the bottom level of the unit, then place the Pizza Stone on top. While holding the smoke box open, use the pellet scoop to pour pellets into the smoke box until filled to the top. Close the box.
Turn left-hand dial to select BAKE. Select WOODFIRE FLAVOR. Set temperature to 350°F and set time to 1 hour. Select START/STOP to begin preheating (preheating will take approx. 10 minutes).
Remove the prepared French toast dish from the refrigerator and discard the plastic wrap. When unit is preheated and ADD FOOD and PRS STRT is displayed, open door and place baking dish on the stone. Close door and select START/STOP to begin cooking.
When 40 minutes remain, open door and cover the dish with aluminum foil. Close door to resume cooking.
When 10 minutes remain, open door, remove dish from oven and discard foil. Pipe the prepared mascarpone mixture throughout French toast and top with remaining ¼ cup blueberries. Return the dish to the oven and close door to resume cooking. If more time is needed, use the right-hand dial to add more time.
When cooking is complete, open door, and remove dish. Serve smoked French toast with maple syrup, and fresh mint, as desired.