https://www.theguardian.com/lifeandstyle/2017/nov/02/how-to-make-the-perfect-parkin?CMP=Share_iOSApp_Other
120g treacle (of Molasses, verkrijgbaar bij Holland&Barret; volg keer verhoudingen Molasses en golden syrup omdraaien proberen)
80g golden syrup (of Glucose stroop, van Turkse winkels, golden syrup bij Hanos)
170g butter, plus extra to grease
200g wholemeal flour
200g medium oatmeal
3 tsp ground ginger
1/2 tsp ground nutmeg
175g soft dark brown sugar
1/4 tsp fine salt
1.5 tsp bicarbonate of soda
1 egg
45ml milk
Heat the oven to 140C. Weigh the treacle, syrup and butter in a medium pan and place over a medium heat until melted together, being careful not to let it boil. Take off the heat. Generously grease a 22cm square baking tin.
Combine the flour, oatmeal, spices, sugar, salt and bicarb in a large mixing bowl, then pour in the treacle mixture, stirring to combine. Beat the egg with the milk and then beat into the batter until it’s just loose enough to pour into the tin.
Bake for about an hour and a half to an hour and three quarters until it’s just firm in the centre and, when pressed, springs back. Allow to cool in the tin for at least 30 minutes, then turn out, slice and either serve warm, or store in a tin for up to three weeks; the texture will carry on improving.