Blueberry coffee cake with streusel topping

In a medium bowl combine 120 g all-purpose flour, a quarter teaspoon of salt, 165 g light brown sugar and a teaspoon of cinnamon.

Work six tablespoons of softened butter in with forks or clean hands until it forms clumps; squeeze a couple of handfuls into rocks and break them up so there is a mix of powder and big pieces.

Preheat the oven to 350F and line a buttered nine by nine inch pan with parchment paper.

Whisk 300 g all-purpose flour with half a teaspoon of salt and two and a half teaspoons of baking powder and set aside.

Beat 10 tablespoons of softened butter with 250 g sugar and the lemon zest on high about four minutes until light and fluffy.

Add the eggs one at a time, mixing in, along with a teaspoon of vanilla; the mixture may break and will come back with more mixing.

Add the flour in three batches, alternating with half of the two thirds of a cup of milk each time, mixing on low and folding the last of it in to clear any streaks.

Fold in two cups of blueberries so they are evenly distributed.

Level the batter in the prepared pan and sprinkle the streusel evenly over the top.

Bake about an hour, checking from 55 minutes, until a skewer in the middle comes out clean.

Cool, then slide it out of the pan.