Preheat oven to 180°C. Grease 2 loaf pans with butter and dust with flour.
In a medium bowl, prepare a dry mixture by sifting together the flour, baking powder, baking soda and salt.
Using a stand mixer on medium speed, cream the butter and sugar. Then add the eggs and vanilla essence and beat for 5 minutes until light and fluffy.
Alternately, add the dry ingredients and yoghurt to the creamed mixture. Don’t over-mix the batter as not to take the air out of the dry mixture. Remove the bowl from the stand mixer, and using a spatula, fold in raspberries and chocolate chips.
Spoon the batter evenly into each pan, filling each ⅔ full.
To prepare the crumble, in a medium-sized bowl, whisk together the flour, brown sugar, cinnamon and butter. Then, top it on the cake mixture.
Bake for 50 to 60 minutes. Allow the cakes to cool for 5 minutes in the loaf pan, then transfer to a wire rack to continue cooling.