1. Preheat the oven to 160oC, gas mark 3, and grease a 1.5l bundt tin really well with butter followed by a light dusting of flour.
2. Cream the butter and sugar together using a handheld electric whisk or stand mixer until light and fluffy, around 5 minutes.
3. Mix the plain flour, baking powder, ground almonds and spice mix together in a small bowl. Add the eggs to the butter and sugar mixture one at a time, beating after each addition. Add 1 tbsp of the dry mix in between each egg to stop the mixture from curdling.
4. Add the remaining dry mix and beat until smooth. Place the marmalade into a small bowl and stir until loosened slightly. Spoon the marmalade and orange zest into the batter and mix one final time to combine.
5. Pour the batter into the prepared tin and bake in the centre of the oven for 40-45 minutes or until a skewer inserted comes out clean. Leave the cake to cool for 10-15 minutes, or until the pan is cool enough to touch. Use a plastic spatula or knife and run it around the edges of the tin if the cake looks like it might be stuck. Invert onto a cooling rack and leave to cool completely before decorating.
6. Heat the marmalade in a small saucepan with the icing sugar and orange juice and simmer until all the lumps of jelly have melted. Place a sheet of parchment under the cooling rack to catch the drips, and then spoon the glaze over the cake. Use a pastry brush to make sure the entire surface is covered.
7. Mix the icing sugar with enough orange juice to make a thick icing suitable to pipe. Pour into a piping bag and drizzle over the sticky cake before topping with orange zest and serving.