1/2stick56g unsalted butter left at room temp for 10 minutes
2/3cup90g plain flour
1/4cup50g light brown sugar
For the cake:
1stick113g unsalted butter, at room temperature
1cup200g caster sugarrefer notes for substituiton
Zest of 1 large or 2 small lemons
3large eggs@ room temp
1tspvanilla extract
Pinchof salt
2tspbaking powder
2cups280g plain flour
1cup240g sour creamI used same qty full fat yogurt
1 1/2cups187g fresh raspberriesI used frozen raspberries
Instructions
Preheat oven to 180C/350F and grease and line an 8 x 8 inch square pan.
Make the crumb topping first: Place butter, flour and sugar into a medium sized bowl and rub between your fingers until you have a coarse breadcrumb texture, some larger lumps are fine. Leave to one side.
Place butter, sugar and lemon zest into a large bowl or the bowl of your stand mixer and beat until light and fluffy, about 2 minutes on medium-high speed.
Add in the eggs and vanilla, scraping sides as necessary, and mix until well incorporated.
Add in salt, baking powder and flour and stir on low until it just starts to come together.
Add in the sour cream/yogurt and continue mixing on low-medium speed until well combined, smooth and there are no lumps of flour.
Tip into your greased pan and spread until level with a spoon/spatula. Sprinkle raspberries all over the cake and press them ever so slightly into the batter.
Sprinkle your crumb topping all over the raspberries, you will have enough to cover the cake completely, a good crumb layer is a necessity!Once you've added the crumb topping, place in the oven for 35-45 minutes (mine took 45 minutes this time round, but previously has taken 35) until risen, golden and an inserted skewer into the centre comes out clean.
Leave to cool in the pan completely, before transferring to a cutting board to slice into 12-16 pieces.
Notes
Crumb cake will keep in an airtight container, at room temperature for 4 days. Lemon flavour is better on the second day, but the crumb topping won't be as crunchy.
I used salted butter for crumb topping for extra flavour and unsalted butter for the cake portion. Also, I added some lemon zest to the crumb as well for extra lemon flavour.
Substitution for caster sugar: to get 1 cup caster sugar, process 1 cup granulated sugar (regular sugar) in a food processor/mixer until fine, but don't powder it like icing sugar.
I used same qty of yogurt instead of sour cream. I whisked the yogurt and measured.
I used frozen raspberries and I didnt thaw them.
Though the recipe calls for an 8 inch tin, I think it's better to use a 9 inch tin. I used an 8 inch square tin and I had leftover batter to make two cupcakes.