A beautiful tea cake from Penny Webster's legacy cookbook, Dining with Vikings. Note that you can absolutely make this in smaller tins to give to friends, or to freeze for later. Just set the timer ten minutes less and give it a check, and bake longer as needed.
Make the topping first, by combining all the ingredients in a bowl, working in the butter until it's a crumbly texture.
Preheat oven to 190C/375F and grease a 10" pan (or a combination of smaller pans) and line the bottom with parchment.
Cream the butter and sugar, add eggs one at a time, then dry ingredients, then the milk. Fold in the blueberries and pour into prepared pans. Sprinkle with topping and bake for 40 minutes, until cooked through and golden.
Cool slightly in the tin and serve warm or at room temperature with softly whipped cream and yogurt.
I replaced the milk with a mixture of creme fraiche and plain yogurt because I didn't have any milk on hand. Sour cream would be a wonderful substitution too.
To help keep the blueberries from sinking to the bottom (I personally didn't mind this), after you measure the flour, take out a large spoonful and toss with the blueberries before folding into the batter.