heat medium saute pan over medium high heat and spray with cooking spray. add diced onions and saute for approximately 1 minute.
add ground beef and saute for approximately 3 minutes, stirring constantly and breaking up beef. meat will still be slightly pink in some areas. drain juice and set aside.
start layering ingredients in crockpot. start with half can beans, all of ground beef, all of brown sugar, all of molasses and finish with the rest of the beans.
set crockpot on low for 4 hours to let the flavors meld. Enjoy!