Blueberry Oat Crumb Muffins

These muffins are one my favorite. A sweet cinnamon-scented batter packed with bursts of tart blueberries, what's not to love?!

Batter 
1/3 cup vegetable oil 

1 egg 

1/2 cup milk of your choice 

2 tsp vanilla extract 

1/2 cup sugar

1/2 tsp lemon zest (optional, but highly recommended)

1 1/2 cups flour 

1/2 tsp salt  

2 tsp baking powder 

1 tsp cinnamon 

1 cup fresh or frozen blueberries tossed with 1 Tbs flour. If using frozen do not thaw them. 
If you have another type of berry on hand use them in place or in addition to the blueberries. 

Topping 

1/2 cup oats - preferably quick-cooking, but old-fashioned works too 

1/2 cup flour 

1/4 cup brown or white sugar

1/2 tsp cinnamon 

1/4 tsp salt 

1/4 cup room temperature butter or 3 Tbs vegetable oil 

Glaze 

1 cup confectioners' sugar 

2 tsp lemon juice 
1/2 tsp lemon zest (optional)

1 tsp milk of your choice 

Preheat oven to 400º F/200°C 

Line a standard muffin tin with paper liners or spray with non-stick cooking spray.

In a liquid measuring cup or medium-size bowl, whisk together the oil, egg, milk, sugar, lemon zest (if using), and vanilla - set aside. 

In a large bowl mix together the flour, salt, baking powder, and cinnamon until well combined.

Make a well in the center of the dry ingredients and pour in the wet ingredient mixture. Mix together until just combined, being sure not to overmix as this will result in a dense muffin.

In a small bowl toss the blueberries with 1 Tbs of flour. This will help them not sink to the bottom of the muffins during baking. 

Gently fold the flour-coated blueberries into the batter. 

In a bowl, mix together the dry ingredients for the topping. Add the butter and mix with your fingers until you have large crumbs. If you are using oil, don't add it all at once, slowly pour it in and mix the dry ingredients with it, pinching the mixture together until you have a crumbly texture. 

Scoop the muffin batter into prepared tins and generously pack the crumb topping on top. 

Bake for 15-20 minutes or until a toothpick inserted in the center of a muffin comes out clean.

To make the glaze, mix together ingredients adding milk until you have a drizzle consistency. 

Allow the muffins to cool before drizzling them with the glaze.