Step 1Combine bread, milk, sugar, butter, eggs, vanilla, raisins, walnuts, cinnamon and nutmeg in bowl. Pour into well-greased 13x9-inch baking dish. Mixture will be very moist but not soupy.
Step 2Bake at 350 degrees until golden brown, about 1 hour. Cool slightly, then cut into squares and serve with Bourbon Sauce.
Step 1Melt butter with powdered sugar in saucepan over medium heat until butter is well incorporated. Remove from heat and blend in egg yolks. Pour in Bourbon, stirring constantly. Sauce will thicken as it cools.