Turn your oven on to the warm setting (170 F). Set a cooling rack over a cookie sheet and place in the oven.
Add eggs, milk, cream, Parmesan, mustard powder, hot sauce, black pepper, garlic, and salt to a blender. Blend until smooth. Pour liquid into a pie plate or an 8x8 dish. Rinse out your blender immediately.
Slice the bread into 1-inch pieces.
Heat a griddle or a large skillet to medium-high heat.
Soak the bread in the egg mixture 1-2 minutes each side.
Grease the griddle or pan with butter.
Fry each piece of bread for about 2-3 minutes, until golden brown. Flip and cook the other side for 1-2 minutes or until browned. Continue with all the bread pieces, replenishing butter as necessary.
Place each finished piece of toast on the cooling rack in the oven.
For the hollandaise:
In the rinsed-out blender, add the egg yolks, dijon mustard, lemon juice, and hot sauce. Blend until smooth. (It's not very much liquid, so I tipped the blender on it's side to help it blend up. See photos.)
In a small bowl in the microwave, melt butter completely so that it's very hot.
Open the top spout of your blender. Turn the blender on low and pour in the hot butter. It should thicken immediately.
Immediately pour the sauce into a measuring cup or bowl. Place the bowl into another bowl of very hot water. (You want to keep the sauce hot, but if you microwave it, it will curdle.)
Pour the sauce over each serving. Whisk the sauce if it starts to separate.
Top each French toast with fresh herbs and extra Parmesan.
Source: French Toast recipe slightly changed from The Kitchn, hollandaise from Allrecipes.