Instructions:
- Prepare the brioche: Slice the loaf into 8 even pieces, about 3/4 to 1 inch thick. If using fresh brioche, lightly toast the slices in a dry pan for 2 minutes per side to dry them out.
- Whisk the Custard: In a large, shallow dish, vigorously whisk together the eggs, milk, heavy cream, sugar, vanilla, cinnamon, and salt until completely uniform and slightly frothy.
- Soak the Bread: Gently place 2–3 slices of brioche into the custard mixture. Allow them to soak for no more than 30–45 seconds per side. Remove immediately.
- Heat the Pan: Place a large non-stick skillet over medium heat. Add 1 tablespoon of butter and 1 teaspoon of oil. Wait until the butter melts and begins to foam slightly.
- Cook the Toast: Place 2–3 soaked slices into the hot pan, ensuring they are not overcrowded. Cook for 3–4 minutes until deep golden brown and caramelized.
- Flip and Finish: Carefully flip the slices. Add another small knob of butter to the pan if it looks dry. Cook the second side for another 3–4 minutes until cooked through and golden.
- Serve Immediately: Transfer cooked French toast to a plate. Repeat the process, adding fresh butter/oil for each batch, until all slices are cooked.