Toast hazelnuts 10-15 mins, let cool, and gently crush ( using a rolling pin).
Split vanilla bean, scrape out seeds and place directly in a small sauce pan with 2 1/2 C half and half. Add the remaining vanilla pod. Warm up the half and half and vanilla on medium heat, stirring occasionally, until almost to a boil. Turn heat off and let cool and seep 20-30 minutes.
Slice the pears.
Melt 2 T butter in a skillet and sauté pears on medium heat until golden, about 8-10 minutes. Add 1 T maple syrup. Simmer for a few more minutes, allowing them to caramelize. Set aside.
Cut bread in to 1/2 inch slices. In a medium bowl, beat eggs, salt, spices, orange zest and 3 T maple syrup. When half and half has cooled, remove vanilla pod, and add a little at time into the egg mixture, mixing it together. (Do NOT add hot cream to the egg mixture, it may cause your eggs to curdle. Either let the cream cool, or temper the eggs, by adding just a little warm cream at a time, mixing in-between… so the eggs gradually warm up.)
Generously butter a 9x 13 inch baking dish. Layer bread, hazelnuts, and caramelized pears pouring all the buttery syrup from the pan evenly over the bread. Pour batter over, using a spatula to ensure it goes in all the cracks crevasses. Let sit at least 30 minutes, so bread can soak up batter, or refrigerate overnight. Right before placing in the oven, drizzle the top with 1 more T maple syrup and sprinkle with a pinch of cardamon. Bake 45-50 minutes until puffed and golden. If your layers measure higher than two inches, you may need to bake longer. Check the middle to see if all the liquid is cooked. I have found that the true test is, if it puffs up, it is done. Melt small dots butter over the top and serve with warm maple syrup.