Using an electric whisk, beat the butter and sugar together until soft and fluffy. Add the eggs and orange zest and mix these in before adding baking powder and flour. Mix until combined. Divide the cake batter into two lined cake tins, then bake in a pre-heated oven (180c / 160c fan) for 20-25 minutes, until both are golden and cooked through, testing the centre of the cake with a skewer. Once cooked, leave to cool completely on a wire rack. Once cool, spread the crème fraîche over the bottom cake. Then spread the orange curd over the inside of the top layer of the cake, before sandwiching the two together. To make the drizzle, add the orange juice to a bowl before adding the sugar cubes. Crush with the back of a fork, keeping some grainy texture. Pour the orange syrup over the cake, then arrange the whole blanched almonds around the edge of the cake.