First, prepare the sauce. Place the blue cheese in a medium saucepan with the milk and butter, and place on the stove over low heat. Stir with a wooden spoon, breaking up the cheese as it melts and stirring into the milk. Once all the blue cheese is broken up, add the parmigiano-reggiano a little at a time, and continue to stir until completely melted and smooth. Remove from the heat and stir in the heavy whipping cream. Set aside to cool.

Cook the lasagna noodles according to package directions, then rinse under cold water and lay out separately so they don't stick.

In a mixing bowl, combine the crab meat, ricotta, mozzarella, torn spinach, and eggs; stir well. Add in the Italian seasoning, garlic powder, and nutmeg; stir well again.

Preheat oven to 375 degrees F and spray a 9 x 12 baking pan with cooking spray. Leaving a 1-inch gap at the top, place about ¼ cup of the crab mixture on the upper end of each lasagna noodle, then roll the side with the mixture up to the bottom end. Place in the baking pan seam side down. Pour the cooled sauce over the top of the lasagna rolls, cover with aluminium foil. Bake in the preheated oven for 30 minutes, or until bubbly and heated through.