Could you adapt this recipe for muffins?

There should be no problem baking that in a different pan. But it's easy enough to find out. Put batter in 2 of the muffin tins for a test run and see what happens. Put a little water in all the tins that don't have batter. If you are not happy w/ the muffins, either bake off the batter in a loaf pan, per the recipe, or adjust the flour and leavener per pieceoflayercake's suggestion, and bake 2 more muffins to test. (or bake all of them if you want to be adventurous!)

Sure...muffins are pretty much mini quick breads, anyway. Without having made this, I would imagine there's not enough flour for the heft that a muffin usually has. I would try bumping the flour up to 2 cups and see what kind of texture you get. Judging from the photo you may want to add another ½ t. baking powder for a bit more lift, too. But again, this is without having made the recipe before.