A person who makes or serves blancmange; someone who prepares this type of dessert.
From 'blancmange' plus the agent noun suffix '-er'. This creates a word for someone specialized in making this particular dessert.
A 'blancmanger' is a beautifully specific word for a cook specializing in one dessert—it reveals how Victorian-era kitchens had such specialists that they got their own job titles.
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