The closest term in the United Kingdom is Tray Bakes. UK versions of Squares tend to be made in shallower pans than the cake pans which are used in North America — thus the word “tray.” Other English-speaking countries such as Australia, New Zealand and the UK may have picked up the idea for “Squares” from North America, as Square recipes appear to predate Tray Bake recipes by many decades.
The “canon” of recipes for Squares was largely defined during the period of the turn of the 1900s, till about the 1950s. New recipes since then are largely variations on a theme.
Squares are usually more dense than cake, though many recipes come close to being cake-like.
Squares recipes can be bake or no-bake. They can be layered, with a base, a filling and a topping. Toppings or icings are often, though not always, baked right with the dessert, rather than being applied later as with cakes.
They tend to use special ingredients such as chocolate, coconut, pineapple, lemons, nuts, etc, all items which would still have been in the luxury range at the start of the 1900s and well into the 1940s.
The cutting into squares is done after cooking, not before. Each piece is called a “square”, though they may occasionally be called “bars”, as in “Nanaimo Bars.” In the United Kingdom, the pieces of a Tray Bake are called slices.
Squares are usually cooked in a cake pan 8 inches by 8 (20 x 20 cm) or 9 x 9 (23 x 23 cm), but can be baked in larger pans such as 9 x 12 (UK — 23 cm x 30 cm) or 9 x 13 (North America — 23 cm x 33 cm.)
Squares are seen as relatively “friendly”, reliable undertakings in the kitchen: while stories of cake failures are legion, stories of Squares recipes failing on people are pretty uncommon. In addition to falling in the “comfort dessert” category, they are often the stars at community social events. They:
- travel well, the first prerequisite;
- look great inside when cut, with layers, etc;
- make for show-piece platters when slices from various kinds are assembled together;
- easily feed large numbers of people;
- the slices can often be eaten out of hand.
In Australia, Lamingtons are a famous type of Squares. A 1912 recipe in the The Kookaburra Cookery Book says that you can cut Lamington Cake (which has evolved into something meant to be served as squares) into squares for presentation.
Advertisement for Lemon Squares. Eaton’s Store Advertisement.
Winnipeg, Manitoba: Winnipeg Free Press. 31 May 1907. page 9.