Line two 13 by 18-inch baking trays with parchment paper. Arrange two racks in the upper and lower thirds of the oven and preheat the oven to 350°F (175°C).

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, brown sugar, and granulated sugar on medium until soft and creamy, pausing halfway through to scrape the sides and bottom of the bowl with a rubber spatula, 2 to 3 minutes. Add the egg and vanilla, then beat on medium to fully combine. Add the almond paste and mix for another 2 minutes. It’s okay if the paste isn’t entirely integrated into the mixture, as any larger chunks will melt as the cookies bake.

In a large bowl, whisk together the flour, rye flour, baking soda, and salt. Add the flour mixture to the butter mixture and mix on low until all the ingredients are well incorporated. Add in the chocolate chunks and mix until just combined.

Portion the dough into golf ball–size scoops (about 65 g each). Flatten each one slightly between your palms and place them on the prepared baking trays, 2 to 3 inches (apart.

Bake for 20 to 25 minutes, rotating the baking trays halfway through from top to bottom and front to back, until they are brown at the edges and the tops are still slightly soft. They will continue to firm up after you take them out of the oven, and to ensure that they stay soft and chewy, it’s better to underbake them slightly rather than overbake. Let them cool on the baking trays for 1 to 2 minutes, until they have firmed enough to transfer to a rack to then cool completely. Store the cookies in an airtight container, where they will stay fresh for up to 3 days.

NOTE: Chop bars of dark chocolate with a large serrated (bread-slicing) knife. That’s the easiest way to keep it from flying around on the cutting board, and yields pieces with different shapes and sizes, resulting in a glorious chocolate chunk (vs. a more generic chocolate chip) cookie.