The first time I ever experienced anything like this was in The Netherlands. I lived and worked there several years ago, and this sandwich (ungrilled) was in the vending machine at work and was also a common sandwich to find at sandwich carts and shops. It was just gouda on a raisin roll, but I'd never thought to put cheese on sweet bread. It's delicious! I've been craving it for the last several days, so I bought some cinnamon raisin bread and some young gouda and decided to grill it up. It's a simple combo, but tasty and works cold or grilled. I was trying to think of a condiment to add and I almost put some tomato chutney on it, but the chutney also contained raisins and I didn't want to go overboard with the raisins. If I had some mango chutney I think that could've made it something worthy of blowing minds.
2-3 slices Gouda
2 slices of cinnamon raisin bread
1/2 tbsp butter
Make a sandwich with the cheese and bread. Spread butter on outside slices of bread. Grill in a frying pan for 5-10 minutes on medium heat until bread is browned and cheese is melty.