I did my "rubbing in" in the food processor so it ended up quite fine and I thought it was way too dry to stick together, but once baked the base was perfectly firm and solid, I suspect I could have done a lap of the house with it in my hands and it would have held together. I guess some of the moisture from the rest of the cake mix seeps in.
2 cups (250g/8oz) SR flour
2 tsp ground nutmeg
125g (4oz) butter
1.5 cups (345g/11oz) brown sugar
.5 tsp bicarb
1 cup (250ml/8 fl oz) milk
.75 cup (90g/3oz) chopped walnuts (pecans, almonds...I don't see why you couldn't use any nut)
1/ Preheat oven to 180ºc (350ºF/Gas 4). Grease and line a 20m springform tin. Sift SR flour and nutmeg int a bowl (I never sift) and add the chopped butter and brown sugar. Using your finger tips, rub the butter into flour mixture until it resembles fine breadcrumbs. (I did this in food processor).
2/ Place half this flour mix into the cake tin and press it down until base of tin is evenly covered. Press it down smoothly (using back of spoon or hands).
3/ Combine egg, bicarb, milk, nuts and add to the remaining flour mix. Stir till mixture is just smooth (except it won't be smooth because you have chunks of nuts in there, stupid recipe)
4/Pour this walnut mixture over the crumb base of the prepared tin and smooth surface with spatula. Back 35-40 minutes or until skewer comes out clean. (In my whizzbang fan forced oven I needed the full 40.) Set cake aside for at least 10 minutes before transferring to wire rack to cook.
Recipe from Family Circle Quick Mix Cakes circa 1996