Pour 1/2 cup water into a medium saucepan over medium heat. Add the sugar and honey and increase the heat to high. Swirling the pan occasionally, cook until the sugar is dark amber, 10 to 12 minutes. Take the pan off the heat and whisk in the butter one piece at a time until completely emulsified. Divide the sauce among the muffin cups. Divide the apple slices among the muffin cups, breaking them in half when necessary to pack all the slices in.