Place the butter, brown sugar and cinnamon in a saute pan over medium high heat and stir until the butter is dissolved; add pears and coat with sugar. Saute for five to seven minutes or until pears are fork tender. Set aside.
In a bowl mix together ground beef, salt, pepper, and onion powder. Divide into four equal patties. Sautée burgers in a large pan with the two tablespoons of olive oil. Cook patties for 7-10 minutes on each side for a medium well burger. When there is only a minute and a half left on the final side of the patties add two pieces of brie to each burger, so the cheese is able to melt. Set aside.
Place the burger on the ciabatta bread, add a few slices of pear to each burger, and top with arugula.