Combine all the ingredients other than the ● ingredients together in a mixer or food processor. Mix or pulse for 3-5 seconds so as not to over mix it.
Transfer what you made in Step 1 to a heatproof bowl and cook for 2 minutes in the microwave. Once it's done, return to the mixer and mix for 3-5 seconds.
Cook it once again in the microwave for 1-1 minute and 30 seconds. Whilst still hot, add in the ● ingredients mixing well with a whisk.
So that the surface doesn't dry out, cover it with plastic wrap. Once it has cooled, chill in the fridge and it's ready.
Add in the coffee at the end to further enhance the flavor and aroma.
This is popular as a filling in my other recipe [Waffle Style Dorayaki with Barely Powder] Recipe ID: 702429
Story Behind this Recipe
It was difficult to mix in the barley powder so I added all of the ingredients into a blender and it went really well.
If you overdo it with the blender, it will become bubbly so be sure to to stop it after a few seconds. The mixture may become sticky so please just give it a whisk at the end. 4 tablespoons of sugar will produce the same sweetness as heavy cream. Adding a little rum will also help give this custard a superb flavor.