Why to try delicious Toll House marble squares
By Ann McDuffie – Tampa Tribune (Florida) May 20, 1967
There’s a neat trick to marbleizing the chocolate morsels throughout the batter. The cookie batter is put into the baking pan and a package of semi-sweet chocolate morsels is sprinkled over the top. The pan goes into a preheated oven for 1 minute to soften the chocolate, then it’s removed and a spatula or knife is run through the batter to “marble” the cookies.
Finally, the whole thing is returned to the oven to continue baking until done. This trick is really simpler than it reads and just about as quick.
Variation – Oatmeal marble squares: Reduce flour to 3/4 cup and add 1 cup rolled oats.
Vintage Toll House Marble Squares recipe card (1962)