Chocolate Souffle

Directions

1. 1
   adjust oven rack to lower-middle position and heat oven to 375 degrees
2. 2
   grease 2 quart souffle dish with 1 tablespoon softened butter, then coat dish evenly with 1 tablespoon sugar; refrigerate until ready to use
3. 3
   melt chocolate and remaining 4 tablespoons butter in medium heatproof bowl set over saucepan of barely simmering water, stirring occasionally until smooth
4. 4
   stir in liqueur, vanilla, and salt; set aside
5. 5
   using stand mixer fitted with paddle, beat egg yolks and remaining 1/3 cup sugar on medium speed until thick and pale yellow, about 3 minutes
6. 6
   fold into chocolate mixture
7. 7
   using dry, clean bowl and whisk attachment, whip egg whites and cream of tartar on medium-low speed until foamy , about 1 minute.
8. 8
   increase speed to medium-high and whip until stiff peaks form, 3 to 4 minutes
9. 9
   using rubber spatula, vigorously stir one-quarter of whipped whites into chocolate mixture
10. 10
    gently fold in remaining whites until just incorporated
11. 11
    gently pour mixture into prepared dish, wiping any batter from rim with wet paper towel
12. 12
    trace circle in batter with your finger, about 1/2 inch from edge of dish (this will help souffle rise nicely)
13. 13
    bake until fragrant, fully risen, and exterior is set but interior is still a bit loose and creamy, about 25 minutes (use 2 large spoons to pull open top and peek inside)
14. 14
    Serve immediately