MEXICAN CHOCOLATE CAKE

Steps:

• Make cake:
• Put oven rack in middle position and preheat oven to 350°F. Butter cake pan well and dust with flour, knocking out excess.
• Melt butter (2 sticks) in a 3-quart heavy saucepan over moderately low heat, then whisk in cocoa. Add water and whisk until smooth, then remove from heat. Whisk in separately sugar, eggs, buttermilk, and vanilla.
• Sift together flour, baking soda, cinnamon, and salt into a bowl, then sift again into cocoa mixture and whisk until just combined (don't worry if there are lumps).
• Pour batter into cake pan and bake until a wooden pick or skewer comes out with a few crumbs adhering, 45 to 55 minutes. (Leave oven on.)
• Cool cake in pan on a rack 20 minutes, then loosen edges with a thin knife and invert onto a plate.
• Make glaze:
• Spread pecans in 1 layer in a shallow baking pan (1 inch deep) and bake until fragrant and a shade darker, 6 to 8 minutes. Cool pecans slightly in pan on a rack, about 5 minutes.
• Melt butter in a 2-quart heavy saucepan over low heat, then stir in half-and-half and confectioners sugar. Add chocolate and cook, stirring, until smooth. Remove from heat and stir in pecans and salt. Cool glaze until slightly thickened, about 5 minutes.
• Spoon glaze over top and sides of cake (cake will still be warm) and spread with a small offset spatula or knife to cover completely.