This is the method I used to make my chocolate infused liqueurs for the 4th of July block party.
3/4 cups sugar
1/2 cup water
1/4 cup cocoa powder
1 1/2 cups tequlia (or vodka)
Put 1/4 cup cocoa powder (I used Omanhene) and 1/4 cup fine baker's sugar in a pint mason/canning jar. Top with tequila. Close the jar and shake to mix it all up. Unseal and heat in a hot water bath to around 150 degrees to help dissolve the sugar and pasteurize the mix. Seal it back up, shake again, and set in a corner for about a week.
Make a simple syrup by boiling 1/2 cup water and stirring in 1/2 cup sugar. Let it simmer a couple of minutes and then remove from heat.
Strain the solids out by filtering through a fine cloth like a flour sack towel or clean dish towel. I ended up pouring some into the center, then closing up around it and twisting the ends to squeeze it through, otherwise the cocoa clogs the cloth and it takes forever to strain.
Put the strained tequila back in the jar and top it off with simple syrup. Close up the jar, drop it in the freezer for a few hours, and serve chilled.