Blueberry Muffins

We saw these on America's Test Kitchen and were drooling.

For Jam:
1 c blueberries (fresh or frozen)
1 t sugar

For Topping:
1/3 c sugar
1-1/2 t lemon zest

For Muffins:
2-1/2 c AP flour
2-1/2 t baking powder
1 t salt
2 eggs
1-1/8 c sugar
4 T melted butter (room temp)
4 T vegetable oil
1-1/2 t vanilla
1 c buttermilk
1 c fresh blueberries


1. Heat sugar and blueberries in a saucepan until a jam consistency.  Set aside to cool.
2. Mix flour, baking powder and salt
3. Mix eggs and sugar, then add butter, oil, vanilla and buttermilk
4. Add blueberries to wet ingredients and fold in dry ingredients
5. Add batter to muffin pan
6. Add 1 t jam to middle of each muffin and swirl into batter
7. Mix sugar and lemon zest topping and sprinkle over batter
8. Bake at 425F for ~18 mins.