Don’t be put off by the longer baking and cooling times for this cake – it’s really simple to make. Dusting the fruit in flour before folding in helps to prevent the berries sinking in the mixture.
Heat the oven to 180°C/160°C fan/350°F/Gas 4.
Beat the butter, sugar and vanilla in a stand mixer fitted with the beater, on medium speed for 2–3 minutes, until pale and creamy.
With the mixer on a low speed, add the eggs, one at a time, beating well between each addition (don’t worry if the mixture curdles slightly – it will come together when you add the flour).
Gradually add the milk and mix well to combine. Using a large metal spoon, fold the flour, baking powder and salt into the mixture, until just combined.
Put the blackberries in a small plastic bag with the extra 1 tablespoon of flour and give them a shake to coat. Gently fold them into the cake mixture until evenly distributed.
Pour the mixture into the prepared tin and bake for 50–60 minutes, until golden brown and a skewer inserted into the centre comes out clean. Turn out onto a wire rack and leave to cool completely (about 1–2 hours).
Meanwhile, make the topping. Using a wooden spoon, beat together the Greek yogurt and honey in a bowl, until smooth.
Once the cake is completely cool, spread the topping on top. Decorate with the halved blackberries and then dot with edible flowers, if using.