Whisk together egg yolks, eggs, half and half, beer, sugar and vanilla.
Coat a 2 1/2 quart baking dish with nonstick cooking spray. Cut croissants in half horizontally. Place bottom halves, cut side up in prepared dish. Sprinkle with dried fruit and walnuts. Cover with top halves of croissants, cut side down. Pour egg mixture over top. Weigh down with another baking dish so croissants get submerged in liquid. Let stand 30 minutes.
Heat oven to 350 degrees F. Cover pudding loosely with foil. Place pudding in a larger pan on oven rack. Pour hot water into larger pan to reach depth of 1 inch.
Bake at 350 degrees F. for 1 hour. Remove foil and bake an additional 30 minutes or until internal temperature registers 160 degrees F. on an instant-read thermometer. Remove dish to wire rack and cool slightly. Dust with confectioners' sugar before serving.