The first step in making this is done in a double boiler, a double boiler is when you have a pan of boiling water with a bowl on top without the water touching it to gently cook the item inside/ Over high heat, bring egg whites and sugar to 160° while stirring or whisking until it reaches the temperature.

In the bowl of a mixer whip the egg white mixture to stiff peaks and keep mixing until the mixture cools, this takes about 10 minutes. After the first minute of mixing, add in the instant coffee. Continue mixing until the sides of the bowl shouldn't be warm if they are, keep mixing.

Then on medium speed add in the butter 1 tablespoon at a time, the mixture may look clumpy, separated, or look runny, just keep mixing.

It will then become thick and when spread with a spatula it's smooth.

If it tastes too buttery, keep whipping it.

If the mixture is runny, put the bowl in the fridge for 10-15 minutes.

Then mix more until it's thick and smooth.