Line 2 baking sheets with parchment paper and preheat the oven to 350 degrees F.
Sift the flour, baking powder, salt and cinnamon together.
In a stand mixer with the paddle attachment, cream the butter and sugar on high speed until light and fluffy. Add the vanilla, then turn the speed to low. Add the eggs, one at a time, followed by the Rumchata. Then slowly add the flour mixture. Add the bittersweet chocolate last, mixing until just combined.
Use a 2-tablespoon scoop to portion out the cookies onto the prepared baking sheets (See notes). Chill for 15 minutes, then bake for 10-13 minutes, or until they look just slightly underdone (they'll set as they cool). Allow to cool for 5 minutes, then transfer to a wire rack to finish cooling.
If you can't find Rumchata, Bailey's Irish Cream is a great substitution.Since this recipe makes a lot of cookies and you want to chill before baking, here's what I typically do. My method requires two or more baking sheets, but you could also use something like a cutting board. When scooping out the dough, place the cookies very close together on a baking sheet (or cutting board) before chilling, so they easily fit into the refrigerator in one place. When it's time to bake, place 1 1/2 - 2 inches apart on a baking sheet. Bake in batches while the remaining cookie dough chills. This does increase the total time of the recipe, but I find it easy and stress-proof.