when flavoring simple syrup, can I just use an extract? If so, what are your favorites and what are your least favorites?

Simple syrup for cakes is generally just to add moisture. You can use it with flavoring or extracts, or even juice. The flavor in the syrup should match or complement the cake flavor. Simple syrup is more necessary when you use genoise or dry layers for cake assembly.

Instant coffee granules dissolved in syrup are good with chocolate cakes. Some other coffee syrups can be used with plain syrup.

I wanted to use almond extract to compliment the almond flavor of the cake, but have never used simple syrup before. Thank you for responding.