I'm planning to try St Germain in my favorite madeleine recipe. Think it will be fabulous!

Liqueurs tend to be milder than extracts, but I love using them in baking. I usually use them as flavoring for whipped cream or custard or buttercream, and the flavors are more prominent if the liqueurs are not cooked. Berries with St. Germain whipped cream would be very elegant, or crepes filled with a St. Germain pastry cream. Souffles are another traditional application - Grand Marnier souffles are classic, but I've made a charteuse souffle that was very boozy and superb.

I love both ST. Germaine and Canto liquers and enjoy mixing them with a variety of wines, sparkling juices, and spirits. I like he idea of adding them to a glaze or mixing into whipped cream as a topping. I have a cookbook called The Irish Spirit: Recipes Inspired by the Legendary Drinks of Ireland. It has lots of recipes using Irish liqeurs (such as Irish Mist, Irish cream, etc) and I bet you could substitue St. Germaine insome of the dessert recipes.

I think St. Germain would pair extremely well with berries.

One of the things I really like to do for a dessert is to make a very simple stovetop fruit sauce to put over a little vanilla ice cream.

Get some frozen berries and heat them in a pan with a very little bit of butter, a little sugar, and some of the St. Germain. In the past I've used orange liqueurs such as Cointreau or Grand Marnier, but St. Germain would work very well. It needs to be cooked just long enough to heat the fruit through and to cook off the alcohol, just a few minutes on medium heat. If you'd like it thicker, you can thicken it with a slurry of cornstarch and a little juice. If you have arrowroot starch instead, the sauce will remain clearer and glossier.

Lots of liqueurs or spirits would work well in this application. As suggested by SavoryKitchen, Domaine de Canton is an excellent liqueur. A little kirsh would be very good as well. Good-quality brandy, cognac or rum would also work.

I've used it in recipes. It's a little to mild for an extract substitute (it adds something, but not enough to stand on its own) that said, in a glaze or syrup, it's great because the floral notes don't cook off in the baking. Also try Domaine de Canton (ginger liqueur) too.

My Nana made a great Galliano bundt cake - boxed mix with a big slug of Galliano in it, and Galliano sugar glaze on top. Sure you could try something similar with St. Germain. I think you'd need more volume than you'd use for extracts, perhaps 1 Tablespoon rather than 1 teaspoon.