Malt Biscuits

From 1922:

One-half breakfast cupful of extract of malt, one-half cupful of sugar, two tablespoonfuls of water, tablespoonful of butter, one-half teaspoonful bicarbonate of soda, and enough flour to make a fairly stiff dough. Put the malt, sugar, water and butter into a saucepan and beat them gently, stirring well till melted. Cool them, and add one cupful of flour, sifted with the soda, and a pinch of slat. Mix well and add more flour if not stiff enough. Roll out thin, cut into biscuits, and bake in a moderate oven for about 20 minutes. They must be watched carefully, as they burn easily.