1920s? LIght Fare Recipes for Corn Flour and "Raisley" Cookery, UK HB, VG
"Raisely", by the way, is a raising agent for baking. For ordinary purposes it should be used in the proportion of: 1 part "Raisley" to 8 parts of flour.". The few copies online that I can find speculate early 1900s to 1930s/40s.