When you think of sugar, you probably imagine piles of refined white sugar, which isn't a bad thing. Refined white sugar has one flavor: sweet, and it's the most common type of sugar found in bakeries and commercial kitchens.
There are many other kinds of sugar, too, and some of them have a much more complex flavor profile than refined white sugar. For example, demerara sugar is a raw, unrefined form of cane sugar that doesn't undergo the extensive refining process that refined white sugar goes through.
Most grocery stores carry it in their baking section or in the natural foods aisle, and you can also find it online at specialty sites like Whole Foods. It is a popular topping for cookies, muffins, and other baked goods, as well as a shortcut for caramelized sugar in creme brulee or other dessert recipes.
You can make a rich simple syrup with demerara sugar just as you would with any other sugar, by adding equal parts sugar and water to a small saucepan over medium heat. Stirring just until all of the sugar crystals dissolve. You can then pour your simple syrup into a glass jar in the fridge for up to a month.
When making your simple syrup, be sure to use an airtight storage bottle and be super clean. You can also add a splash of Everclear to extend the shelf life.