Add cocoa and 'cook' for 1-2 minutes while stirring. The cooking brings out the chocolately goodness in the flavour.
Remove from heat, stir in sugar
Beat in eggs one at a time. Beat well between each addition, the mixture should become nice and glossy
Add almonds and vanilla, mix/beat well
Add flour and baking powder (I don't even bother to sift them, I just sprinkle the baking powder over the flour), mix well
Pour into a baking paper-lined loaf tin
Add the frozen blueberries on top, gently pushing them into the surface of the mix
Bake at 180 degrees celsius for 30-35 minutes. You want the surface to be just firm and to just start cracking, it will also just be pulling away from the edges of the pan. (be careful not to overcook them, if you overcook them they loose their gooey chewiness and can become a bit dry)
Notes
Gluten-free: as this recipe has a relatively low amount of flour you can pretty much swap standard flour for any flour. Rice flour, GF Baking Flour all work brilliantly. Spelt flour also works but note spelt is not gluten-free. You can even swap the flour out for extra ground almonds, it just makes a heavier brownie.
Nut-free: Swap out the almonds for desiccated coconut. Even if it is not for allergy reasons, the coconut version is equally as delicious
Raspberries are optional: You can leave them out completely or swap to another berry
Go Citrus: Ditch the cocoa and add 2 tablespoon lemon juice and 2 teaspoon lemon zest at step 5. (If you are going for a lemon inspired brownie you can stick with the almonds or try coconut as an alternative)
Go Jaffa: Add 2 tablespoon Orange Juice and 2 teaspoon orange zest at step 5
Go Nuts: Add extra whole nuts, almonds, walnuts, cashews, macadamia, whatever your heart desires. (add around ½ a Cup)
Add MORE Chocolate: I sometimes stud the top with chocolate chunks. My Husband likes blueberries with white chocolate.