This auxiliary label was found on the window of one of the food shops.
Photo: Moscow, New Arbat, 4th of September 2009.
Let's get deep into these three words. These are КОНДИТЕРСКАЯ, БУЛОЧНАЯ and ГАСТРОНОМИЯ. To avoid following that bad style of capitalizing everything, I will use lower cases where it is applicable from now on.
So. Кондитерская is translated as confectioner's. If you'll look into the dictionary, you will find that this word is both an adjective and a noun. In the usage shown above it is a noun.
The second word булочная means the bakery. It also may be considered in some seldom occasions as an adjective, but here it is a noun.
And the third word гастрономия is groceries, or just food. This is a noun only.
As you could notice, each word ends with -я. But this fact alone gives nothing about the grammatical category of the words. We need to consider two letters in the endings of these words. For the first two ones they are -ая, and for the third one -ия.
The ending -ая usually indicates that a word is an adjective, and more precisely—feminine adjective. Compare, for instance, красная (she) red, or высокая (she) tall. In Russian, there is a category of adjectives which may be used as nouns. These two words are the examples. Being grammatically adjectives, the words change their form according to the rules for adjectives, even if used in a sentence as nouns.
With the word кондитерская as an adjective you may expect to encounter it preferably in plural form when someone says about the final production, for example: кондитерские изделия (plural: confectionery, literary: confectionery items). Single form is normally used when referring to things which take part in the process of creation, for example: кондитерская фабрика (confectionery plant) or кондитерская промышленность (confectionery industry).
The word булочная, which is of dual nature as well, might be used as an adjective even to refer to the baker's shop as well. Thus you may say both булочная (noun: bakery) and булочная лавка (adjective: bakery small shop). Not that in both cases the form of the word remains the same, while its grammatical category changes. An adjective is often used in a compound word хлебобулочная (literary: of bread and of bakery), for instance: хлебобулочная промышленность (bakery industry).
And finally, another ending, -ия, indicates a feminine noun. Compare the word химия (chemistry), which has this ending as well. Гастрономия is also a common word for referring to a department in a store, where they sell food. There exists a single word гастроном (food shop).
All those three words on the photo can be used separately, for example they are used as generic names of the food shops (each one specifying the type of food you may buy there). Note also that the lack of punctuation and small letters converts the three separate words into grammatically correct (but having no meaning) phrase «кондитерская булочная гастрономия» (confectionary bakery groceries), where only the last word is a noun, and the first two ones are its attributes (attributes are then adjectives).
