Home baking may be a humble art, but its roots are deeply planted. On an island in Sweden a grandmother teaches her granddaughter how to make "slagbrot," a velvety rye bread, just as she was taught to make it by her grandmother many years before. In Portugal, village women meet once each week to bake at a community oven; while the large stone oven heats up, children come running for sweet, sugary flatbreads made specially for them. In Toronto, Naomi...