Preheat oven to 325°F. Butter and flour a 10-inch-diameter spring form pan.
In a microwave safe bowl, combine chocolate and butter, and heat for 40 seconds on HIGH for butter and chocolate to begin to melt. Stir; continue heating for 10 seconds at a time until chocolate and butter are almost completely melted, remove from microwave and stir so that residual heat will complete the melting.
Stir in Cholula Chipotle and 1 teaspoon of chipotle chili powder, and set aside to cool a bit.
In large bowl, beat eggs and granulated sugar until well blended and starting to thicken. Sift flour, baking powder, and salt into egg and sugar mixture.
Next, fold in the chocolate-butter mixture. Pour batter to prepared pan.
Bake about 50 minutes, or until tester inserted into center comes out clean. Cool completely in pan on rack. Cut around pan sides to loosen cake. Release sides of springform. Whisk together chipotle chili powder and powdered sugar and gently sift over cake. Slice into wedges and serve.
This cake can be made 1-2 days ahead, and keeps well covered with foil and stored at room temperature.