Blueberry jam muffins

This is a Cook's Illustrated recipe that addresses the only real problem with blueberry muffins:  you taste mostly muffin, and only a little blueberry.  The trick is to boil down some of the berries into jam, and then stir them into the muffins just before baking.

In a small saucepan, boil and mash until reduced to a thick jam:

1. 1 c (5 oz) blueberries, fresh or frozen
2. 1 t sugar

In a mixing bowl, whisk to combine

1. 2 1/2 c (12 1/2 oz) flour
2. 2 1/2 t baking powder
3. 1 t salt
4. 1 c (5 oz) blueberries, fresh or frozen

If using frozen berries, rinse them under cold water and dry them before adding them to the flour mixture.  In a separate bowl, whisk together

1. 2 eggs
2. 1 1/8 c (8 oz) sugar
3. 4 T (1/2 stick) butter, melted
4. 1/4 c vegetable oil
5. 1 c buttermilk
6. 1 1/2 t vanilla
7. zest of one orange (optional)

Gently fold wet and dry ingredients together, just until moistened.  (Some spots of dry flour may remain.)  Spoon batter into 12 greased, standard size muffin cups (cups will be full).  Divide jam among cups, swirling into the batter with a chopstick.  Sprinkle sugar over tops of muffins.  Bake at 425 for about 17 minutes, just until a toothpick comes out clean.  Cool for 5 minutes in the pan before transferring to rack to cool.

If using the orange zest, you can also make an orange glaze out of the orange juice and powdered sugar (approximately 1 cup) -- top the muffins with glaze before serving.  If not using the orange zest, you can incorporate lemon zest into the sugar used for topping the muffins.