Preheat oven to 375 degrees. Line a 13 X 18 baking sheet with parchment paper. Place the biscuits on the pan and place in oven to bake for 13-15 minutes or until golden brown. Take biscuits out of the oven and cut them in half. Place the biscuits halves back on the same baking sheet. Evenly spread the apple butter evenly to the tops of all 16 biscuits halves. Fold each ham slice in half and place one slice on top of the apple butter biscuits. Add 1 tomato slice on top of the ham. Evenly divide 6 TBSP basil on top of the tomato slices. Sprinkle the sunflower seeds evenly over each slammies. Top off slammies with 1 slice of swiss cheese. Place slammies back into the oven and bake for 5-7 minutes or until the cheese has fully melted. Take out of the oven and sprinkle the top with the remaining basil and serve.
I make these often for a quick lunch meal. When I started making these years ago my daughter was younger and couldn't pronounce sandwiches correctly. She would call them slammies. So the name stuck. Now my son will tell you that we call them slammies, because you can slam then down for a quick lunch. Whatever version you like is fine. My family just knows them as being good.