Recipe Instructions:
1 cup superfine sugar (see note above)
1 tablespoon (1/2 fluid ounce) Angostura bitters
Champagne or sparkling wine for serving
Lemon twists for serving (optional)
Combine sugar and bitters in a bowl and stir until liquid is evenly distributed. Use your fingers to pinch the mixture if needed, to make the mixture uniformly pink.
If using molds, press the mixture into molds, packing it down as much as possible. Microwave at 50% power for 20 to 30 seconds. Alternatively, you can let the molds sit out overnight to dry and harden. Once set, pop the cubes out of the mold.
If not using molds, heat the oven to 250° F and line an oven-safe baking pan with parchment paper. (The cubes pictured were made in a standard 9- x 5-inch loaf pan.)
Pour the sugar onto the parchment paper. Pack the sugar into the base of the pan very tightly with a spatula, meat pounder, or another tool that is stiff and flat. The height should be similar to a commercial sugar cube, around 1.27cm/1/2 inch.
Using a thin knife, score the sugar into a grid of cubes of the size you want, slicing all the way through the layer of sugar. Put the pan in the oven to dry for 1 hour.
Remove the pan of sugar from the oven and let the sugar cubes cool for at least 10 minutes.
Break up the cubes. Pull the sugar cubes out of the pan and break them apart with your hands or something smooth and sturdy like a table knife or bench scraper. If cut properly, they will break fairly easy.
Store the sugar cubes in an airtight container. To serve, put a sugar cube in a coupe glass or Champagne flute and pour Champagne or sparkling wine over. Garnish with a lemon twist if you like.
