Preheat the oven to 350 and line 12 muffin cups with liner (or spray them really well with nonstick spray).

In a small bowl whisk together the flour, sugar, baking powder and salt. In larger bowl whisk the oil, egg and buttermilk. Add the dry ingredients to the wet ingredients bowl and whisk gently, just to combine.

Gently fold in the blueberries.

Scoop (I use a cookie/muffin scoop which is a slightly smaller version of an ice cream scoop) the batter into the muffin pan and let it rest while you make your streusel topping.

To make the topping combine all the ingredients in a bowl. Using a spatula, a fork or (most easy) your fingers combine all the ingredients to make a crumbly, almost shortbread-like mixture.

Spoon the streusel mixture on top of each muffin and GENTLY pat into the batter. Make sure to do this gently as you don’t want to smash the nice domed muffin top.

Bake for about 25-30 minutes. These are done when the top springs back to the touch or a toothpick inserted into the center comes out clean. The streusel topping will be slightly golden in color as well.

Let them cool in the muffin pan for 10 minutes before transferring each muffin to a cooling rack.