Preheat the oven to 180°C and grease and line a loaf tin.
Start by making the filling as this needs to firm up in the freezer whilst you make the cake. Add all the ingredients to a pan on a medium heat. Stir until they have all melted and combined and the mixture has thickened slightly. Spoon the mix out into a bowl or onto a plate so that you have a thin layer and then place into the freezer.
Next, add the oats to a food processor and blend until you have a course flour.
Add the ground oat and all the cake ingredients to a bowl and mix well. Spoon half of the mixture into the lined tin and set aside.
Take the filling from the freezer and if it is firm, roll into sausage shapes and place throughout the middle of the honey cake. Add the rest of the cake mix on top and place into the oven to bake for 40 minutes.
Whilst the cake bakes, blend the frosting ingredients together.
Once the cake has baked, leave it to cool in the tin for at least 15 minutes. Remove from the tin, frost and serve!