Coffee cake with cinnamon filling and streusel

Cinnamon filling: mix the light brown sugar, flour and cinnamon in a small bowl and set aside.

Streusel: mix flour, light brown sugar, cinnamon and salt in a medium bowl, breaking up any lumps of brown sugar with a fork.

Cut the cold butter into small pieces and work it in with clean fingers until the mixture resembles wet sand; squeeze and break apart for larger crumbles.

Preheat the oven to 350.

Whisk flour, salt and baking powder together in a separate medium bowl and set aside.

Cream the butter for a minute until there are no lumps.

Add the granulated sugar slowly, then the light brown sugar, and mix about three minutes until light and fluffy, scraping the bowl down after about 40 seconds.

Add the eggs one at a time, letting the first incorporate before the second, scraping down between.

Mix in the room temperature sour cream until smooth, then the vanilla.

Add the dry ingredients on the lowest speed and stop while streaks of flour remain; finish by hand with a spatula until the flour just disappears.

Spread half the batter into an 8 by 8 inch pan lined with parchment paper.

Sprinkle the cinnamon filling evenly over the batter, then dollop the remaining batter on top and connect it with a spatula, spreading in one direction.

Sprinkle the streusel over the top, going lighter in the centre so it does not sink.

Bake at 350 for about 55 minutes, until a skewer inserted in the centre comes out clean.

Glaze: whisk the powdered sugar, vanilla and milk together.

Lift the cooled cake out by the parchment, drizzle with the glaze and cut.