Instant coffee and instant espresso add flavor quickly. I recommend that people always keep a jar of instant espresso powder or instant coffee in the fridge. I like these freeze-dried forms because they add flavor immediately, without needing to steep as beans do. For instance, you can mix a little powder into ganache or pastry cream while it's warm to quickly give coffee flavor to the dessert. It also allows for a more standard result, since people brew coffee so differently, ranging from really weak to really strong.
Coffee liqueurs add sweet coffee flavor with a zing.
When I want to jazz up a dessert, I turn to coffee liqueurs like Kahl a and Tia Maria. For example, I'll mix some into vanilla cr me anglaise for a coffee-spiked custard sauce. Because the alcohol-based flavors diminish when cooked, I generally add liqueurs to desserts after they're cooked. Brew a strong cup of coffee for best results in baking To get the most flavor when using brewed coffee in a recipe, I almost always use espresso because it has a strong, dark flavor. But that's at the restaurant, where I have access to an espresso machine.