If you do not find crema in the dairy case, you may find this, usually stocked with such things as evaporated milk. It's pretty close in thickness to yogurts that have not been artificially thickened or strained. It is not a replacement for yogurt for all purposes. It has a higher butterfat content and a different pH, since it has not been fermented to produce the lactic acid of yogurt. If a recipe uses baking soda, it may be prudent, when using plain cream in place of yogurt, to add an acid component, like lemon juice, to work with the soda, or adapt the recipe to baking powder.