Cream butter & sugar. Preheat oven to 180°C (350°F). Grease and line the base and sides of a 15cm (6-inch) cake tin with parchment paper. Using an electric mixer fitted with the paddle attachment, beat the butter and sugar until pale and fluffy.
Add the eggs. Add the eggs, one at a time, beating well after each addition. Make sure to scrape down the base and sides of the bowl before and after beating the eggs in.
Add in the flavourings. Add in the honey, orange zest and orange blossom water and mix until combined.
Add the dry ingredients: Add the almond meal and baking powder and mix with a rubber spatula until you can still see a few flour streaks. Note, the batter is fairly thick which is what it's supposed to look like.
Bake! Spoon the mixture into the cake pan. Bake for 30-40 minutes or until a skewer comes out clean when inserted into the centre. If the cake browns too quickly then tent with aluminium foil. Once baked, remove from the oven and allow to cool in the pan for ten minutes before turning out onto a wire rack and allow to cool completely.
Make the orange honey syrup. Whilst the cake is cooling, add the orange juice, honey and light brown sugar into a small saucepan and bring to the boil. Boil gently for 5 minutes and then set aside to cool. The syrup will thicken as it cools.
To serve. Once the cake has cooled completely, spoon the Greek yoghurt onto the top of the cake and smooth it with the back of the spoon. Sprinkle the pistachios over the top and drizzle with orange honey syrup. Slice and serve immediately.