How to Make It
Process chocolate wafers in a food processor until completely crushed, 1 to 2 minutes. Add melted butter and ¾ cup of the chocolate spread. Process until thoroughly combined. Line the bottom and sides of a 9-inch square pan with foil, leaving a 2-inch overhang on all sides; lightly grease foil with cooking spray. Press the cookie mixture into the bottom of the prepared pan.
Place the chocolate chips and remaining chocolate spread in a medium-size microwave-safe bowl. Microwave on medium until the mixture is melted and smooth, about 2 to 2½ minutes, stirring every 30 seconds. Pour mixture into the prepared pan, spreading it evenly over the chocolate crust with the back of a spoon or a small offset spatula. Sprinkle with ⅛ teaspoon of the flaky sea salt. Cover and chill 30 minutes. Before serving, sprinkle with the remaining ⅛ teaspoon salt and cut into 1½-by-1-inch bars. To store, refrigerate in an airtight container for up to 5 days.