What is insoluble in drinking alcohol, but edible? What substances are edible for human consumption, but will not mix with alcohol? What is a substance that would block alcohol from mixing with its counterparts in a product?
For example: You make a cupcake and want an alcohol shot in that cupcake. What substance could the alcohol shot be contained in so it wouldn't disperse into the cupcake, but still be edible?
Ethanol does not dissolve chocolate, which consists mostly of butter and sugar. These mini alcohol filled chocolates are very common party candies. You could try inserting one of these into your cupcakes after you have baked them.

You could also try making a mold for a gelatin-based shot cup, as gelatin is also insoluble in ethanol. Gelatin is capable of absorbing alcohol, however, so I do not recommend making these too far in advance, lest they turn soggy.