Preheat oven to 350°F. Line an 8x8 baking dish with parchment paper. Overhang the parchment paper on both ends by a few inches. This is very important as the brownies will still be very soft when they come out of the oven and the parchment paper will allow you to take the whole square of brownies out of the pan with ease.
Add all ingredients, except the chocolate chips and powdered sugar, to the bowl of a food processor. Process until smooth, stopping occasionally to scrape down the sides as necessary.
Remove the blade and set aside. Add the chocolate chips to the batter and gently stir to incorporate.
Spread the batter evenly into the prepared pan.
Bake for 35 to 40 minutes. The top should be set, but the center will still be soft. A toothpick will not (and should not) come out clean.
Let cool in the pan for 10 to 15 minutes. Carefully lift them out of the pan by holding onto the parchment paper overhang. They will probably still be soft and "bend" a little. This is ok, just be careful not to pull up on the sides too hard and break them.
Let cool on a wire rack for another 20 to 30 minutes. The brownies should be firmer now, but still soft and fudgy. Carefully cut out into heart shapes or into bars.
Once the brownies are completely cool, sprinkle with powdered sugar, if desired.