Steel-cut oatmeal muffins

I've been craving a nubbly, fluffy, steel-cut oatmeal muffin for some time.  I could have sworn it was something I'd made before, but I couldn't find any similar recipe.  So I looked around and settled on this one that sounded like what I wanted, but I did have to make some adjustments.

To make a dozen muffins, here's what I used:

1½ cup all-purpose flour
1/2 cup whole wheat flour
1/4 3/4 cup sugar
4 teaspoons baking powder
1 teaspoon cinnamon
1/2 1/4 teaspoon fine salt
1 large egg
1 cup cooked steel-cut oatmeal
1/2 cup whole milk
1½ teaspoon vanilla extract
2 tablespoons unsalted butter, melted and cooled slightly
1/2 cup chopped walnuts

Preheat the oven to 400°F, and grease a 12-cup muffin tin. In a large bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt.  In another bowl, lightly beat the egg.  Add the oatmeal to the egg, and mash with a fork to break up clumps.  Add the milk, vanilla, and the butter, and stir or whisk to combine.  Pour the wet mixture into the dry mixture, and stir briefly to just combine.  Divide the batter evenly between the wells of the prepared muffin tin.  Sprinkle tops with walnuts and press in to secure.  Bake for 15 to 20 minutes, or until a toothpick inserted in the center of one of the muffins comes out clean.  The muffins won't brown much on top and might even look a little anemic, but that's okay.

Although the tester came out clean after 15 minutes, I think these could have used a few more minutes in the oven.  I'd also knock the sugar down to 1/2 cup and try that.  (I wanted them sweet enough to eat alone, but they were  slightly too sweet.)  Considering some muffin recipes add up to 1½ cups of sugar (gah!), these were still only mildly sweet.

I tend to cook oatmeal fairly dry and perhaps a little "al dente," which might explain why my batter was VERY thick.  I added another splash of milk, but I wish I hadn't.  Perhaps extra time in the oven would have fixed the texture, but these were ever so slightly gummy, rather than fluffy.  It could have been that extra milk, though.  Perhaps they could have used another 1/2 teaspoon of cinnamon, maybe a little nutmeg, and a little less vanilla.  I meant to use brown sugar in them but forgot---I think that would be a nice addition.  A touch more salt would be an improvement as well.  So, like, basically a whole different recipe.

Conclusion:  These were good, but didn't quite hit the mark.  I wanted something more nubbly, more hearty, and with a more satisfying flavor. 

Recipe:  Left-over Oatmeal Muffins via epicurious (adapted from The Fannie Farmer Cookbook)