Slice sausages lengthwise in half and in half again crosswise. Set aside for later.
Slice apples into ½-inch slices and cut out core and seeds.
In a fry pan, melt butter on medium-high heat. When butter starts to brown, drop in sage leaves, one or two at a time. Cook a few seconds each until they start to brown and remove from pan to paper towel to cool.
In same pan, add apple slices and cook until just slightly heated. Remove from heat.
In same pan, place Polish sausage slices, cut side down, and heat until just browned slightly. Remove from pan.
Assemble 2 apple slices, 4 sage leaves, 4 pieces of Polish sausage (equivalent of one sausage), and 3 slices of Brie on bread. Top with another slice of bread to make a sandwich.
Spray panini grill with cooking spray on both sides. Place sandwich in panini grill and cook for about 5 minutes, until toasted and cheese melts. Remove from grill. Cut in half. Enjoy!