I was raised on a macrobiotic diet, but my parents were fanatical about their Peet's coffee. And although I wasn't allowed much in the way of sweets as a child, when we visited Peet's to stock up on beans, my parents let me indulge in a chocolate bar while they sipped steaming cups of French roast.
I've associated coffee with chocolate ever since, and these cookies are a childhood memory personified. (The addition of dark rum is a nod to my grown up tastes.) —flourchild
semi-sweet chocolate chunks or chips, divided
Heat oven to 325 degress F and line two 13x18" baking sheets with silicone baking mats or parchment.
In a small saucepan over very low heat (or in the microwave), melt half the chocolate with the butter, stirring frequently and watching it carefully to ensure it doesn't burn or seize. Remove from heat and set aside to cool slightly.
In a medium bowl, whisk together the flour, cocoa, baking soda, baking powder and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment (can also be done by hand or with a handheld mixer), beat the eggs, sugars, instant espresso powder, vanilla and rum (if using) on medium-low speed until well combined. Add the chocolate-butter mixture and beat again to incorporate. Add the flour mixture and remaining chocolate and beat on low speed until a sticky dough forms (it will resemble brownie batter), scraping down the sides and bottom as needed to ensure the mixture is well combined. Be careful not to overbeat.
Using a tablespoon or 1 1/2 inch cookie scoop, drop the batter onto the prepared baking sheets, spacing two inches apart and from edges. Bake for 12 to 14 minutes, rotating baking sheets (front to back and top to bottom) halfway through. The cookies are done when the tops are cracked and the edges are set, but the interior still appears relatively wet (see photo, above). Remove baking sheets to cooling racks for two minutes, then remove cookies from the baking sheets to cool completely. Tip: If using parchment paper, slide the paper (with cookies on it) directly from the baking sheets to the cooling racks. Cookies will keep for 2 days in an airtight container at room temperature, for a week in the refrigerator or up to a month in the freezer (be sure to defrost them in the container or wrapping to prevent condensation from forming on the cookies as they thaw).