No.
Why would you think to capitalize the word vanilla any more than you would think to capitalize strawberry, chocolate, or mint?
There are, of course -and as always-, exceptions.
1.) Capitalize if the flavor is a brand name, in other words, a registered trademark.
also:
2.) Capitalize any word in a flavor name (or anything else) which is the name or adjective form of a country, state, city, region or any other proper name.
Examples of these exceptions:
Do you like my Grand Marnier cupcakes?
Here are some Drambuie cupcakes.
I could eat a dozen French vanilla cupcakes!
Mom baked two German chocolate layer cakes.
"I love Boston cream pie!"
Have a glass of Tahitian vanilla coconut milk.
"This isn't just any old chocolate bar. It's is a yummy Brazilian chocolate one!"
"My favorite treat at Basin-Robbin's is their Rootn' Tootn' Rum Chocolate ice cream."
(In this case even 'rum' and 'chocolate' are capitalized because they're parts of a registered trademark, hence the whole group of words is one proper name.)
"My sister is a baker. She invented a super new flavor of cream puff. She calls them her Montenegro Vanilla cream puffs" (Here vanilla is capitalized because it's part of a registered proper name and may or may not taste anything like 'regular' vanilla.)
Get it?
Yes, you should capitalize "Vanilla cupcake" in a sentence because it is a proper noun phrase that refers to a specific type of cupcake.
Yes, you should capitalize the word "scurvy" if it is the first word in a sentence or if it is part of a proper noun or title.
No, it is not necessary to capitalize "birthday card" unless it is at the beginning of a sentence or is part of a title.
No, you do not capitalize the word "occasion" unless it is at the beginning of a sentence or part of a title.
No, you do not capitalize the word "writer" unless it is at the beginning of a sentence or part of a title.
If its the first word
yes why wouldnt it be
You do not capitalize chickenpox in a sentence. The exception is if the word is the first in the sentence.
no or at least not any more than i capitalize the word sentence in a paragraph
No, it is not necessary to capitalize "birthday card" unless it is at the beginning of a sentence or is part of a title.
Never. ANSWER: only if the word is the beginning word in the sentence.
No.
no
Yes, when referring to the Islamic dietary laws, the word "Halal" is typically capitalized. It is a proper noun and specific term that denotes food that is permissible for consumption according to Islamic teachings.
You do not capitalize the word quarterback unless it is at the beginning of a sentence.
No, the word lunch is not capitalized in a sentence. You would only capitalize it if it was part of a title (e.g. it was a word in a book title).
No you do not capitalize artist in a sentence
No - not unless it's the first word of the sentence.