Mix together butter, sugar, salt, mixed spice and treacle.
Add eggs one at a time.
Stir in the fruit and flour in alternate batches until thoroughly mixed.
Use a metal pan about 10\\\" wide x 5\\\" high.
Line sides and bottom of pan with wax paper.
Allow the paper to extend up over the sides by an inch.
Put in round pan and bake at 325 F for approximately 1 hour.
Then down to 300 F and continue cooking for at least 2 hours.
Check, if the cake is done, by inserting thin instrument until it comes out clean.
Store upside-down (you put the icing on the bottom and sides).
Leave for about 2 weeks in an airtight tin.
Poke holes a few inches down into bottom of cake.
Pour over sherry or brandy.
Repeat this procedure two or three times over a two day period.
Keep stored in airtight tin.
Leave a few days to dry and ice with the royal icing.
