An assembly is mounted to a soft serve confection freezer. It includes a set of modules in a circular array and separately replaceable in a magazine. Each module supports a container storing a dry food ingredient in particulate form, and has a motor driven product impeller for controlled discharge of particulates from the container to a blender assembly. The blender assembly has a housing and screw-type auger of cooperating configurations and which cooperate with a central passageway for frozen confection flowing from the freezer, to blend solids into the confection and discharge into a customer's container for immediate consumption. Control panel selection of ingredients by the operator according to the customer's order, is provided. Components are arranged to facilitate cleaning. A system for control panel selection by the operator of liquid additives to the flowing confection, is provided to accommodate the customer's order.