I will admit upfront that I used a ready-made sweet pastry shell for this. I bought it ages ago as had never seen them before, and it seemed like a good shortcut. I have been wondering what to make with it and then came across this lovely treacle tart recipe from Marie Claire. See here for the recipe.
I found that the quantities given did not make nearly enough filling for my pastry shell, although the recipe says it is for a 20 cm dish. If I made it again I would use a Mary Berry recipe which uses a LOT more golden syrup.
This is a very easy recipe though as the filling is just made of golden syrup, fresh breadcrumbs (grate slices of bread if you don’t have a good processor) and lemon juice.
Here is the end product. It tastes nice but there is not enough filling.