Heat the oven to 175 C / 350 F. Line a 20 cm / 8-inch square baking pan with parchment, leaving overhang on two sides.
Place the pitted dates in a bowl, cover with the hot water, and let them soak for 10 minutes until soft. Drain well.
Transfer the drained dates to a food processor with the tahini, eggs, and vanilla. Blend for 1 to 2 minutes until smooth and glossy, like a thick caramel.
In a separate bowl, whisk the cocoa powder, almond flour, baking powder, and salt together.
Pour the date mixture into the dry ingredients and fold with a spatula until no streaks of flour remain. The batter will be thick, closer to frosting than cake batter.
Fold in half the chocolate chips. Scrape the batter into the prepared pan and smooth the top. Scatter the remaining chocolate chips over the surface.
Bake for 26 to 28 minutes, until the edges look set and a toothpick comes out with a few moist crumbs, not wet batter.
Cool the pan on a rack for at least 30 minutes before lifting the brownies out. Cutting them warm will make them crumble instead of holding a clean square.
Slice into 16 squares and serve.