Instructions

1. Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving an overhang in order to pull the bars out.
2. Using an electric mixer, beat butter, sugar, and salt until light and fluffy. Add flour, cocoa powder, and coffee powder, and mix on low just until combined. Press dough into the bottom and 1/2 inch up sides of prepared pan; prick all over with a fork. Bake until lightly golden, 15 to 20 minutes.
3. In a large bowl, whisk together egg yolks, condensed milk, and passionfruit juice until smooth. Pour over hot crust in pan; return to oven, and bake until filling is set, 25 to 30 minutes. Cool completely in pan.
4. Refrigerate until filling is firm, about 2 hours or up to 3 days. Dust with powdered sugar, then cut into squares and serve.