somniloquence

For the meat, you probably need to cook it a little longer in the slow cooker for a larger amount of meat, but I think you're good on the beans and liquid (just add a little more water than you might normally - 1/3 or 1/2 cup more).

You can bake the cake in a 9x13" pan - same temperature but it might a little longer in the oven than the box says - check it at the time the box says and if the skewer still comes out wet, give it another 4-5 minutes.