Preheat your oven to 400°F (200°C) and generously butter a medium-sized roasting tin or baking dish.

In a large mixing bowl, stir together the self-raising flour, pinch of salt, shredded suet, and the 1 tablespoon of sugar until well combined.

Gradually add the milk while stirring with a knife, adding just enough liquid to bring the mixture together into a soft, slightly sticky dough.

Tip the dough onto a lightly floured surface and gently knead it for a few seconds until smooth, being careful not to overwork it.

Roll the dough out into a rectangle approximately 8x12 inches in size and about 1/2 inch thick.

Stir the jam to loosen it, then spread it evenly over the dough, leaving a clear border of about 1 inch around all edges.

Brush the clean border with a little milk, then carefully roll up the dough from the short end to form a snug log.

Transfer the roll to the prepared baking tin with the seam side facing down to prevent it from unrolling during baking.

Brush the top of the roll with a little milk and sprinkle generously with extra sugar to create a crunchy crust.

Bake in the preheated oven for 35 to 45 minutes, or until the pudding is risen, golden brown, and firm to the touch.

Remove from the oven and let it rest for 5 minutes before slicing into thick rounds to serve warm with custard.