The walnuts add a textural contrast to the very moist crumb of the pumpkin cake. This recipe is based on one from the Miette cookbook, along with the chocolate glaze we used at Tante Marie’s Cooking School. Be sure to let the glaze cool down substantially so that it drizzles slowly and most of it stays on the cake. Makes one 10-inch bundt cake or about 15 mini-bundt cakes (depending on the size of your mini-bundt pans). The cake freezes well, wrapped twice in plastic wrap, for up to 2 months. Wrap and refrigerate to serve within three days of baking.
Preheat the oven to 350 degrees. Liberally butter the bundt pan(s). Dust with flour and tap out the excess.
In a small bowl, whisk together the flour, baking soda, cinnamon, nutmeg, cloves, and salt.
In the bowl of a stand mixer fitted with the whisk attachment, combine the eggs and sugar on medium speed until lightened in color and fluffy, about 2 minutes. Reduce the speed to low and slowly pour in the oil until combined, then increase speed to high for 1 minute. Switch to the paddle attachment and add the pumpkin puree, mixing on medium speed just until combined. Add the flour mixture in three additions, mixing just until combined after each addition (about 5 seconds each time, on low). Remove the bowl from the mixer, scrape down the sides with a rubber spatula, and mix in the walnuts.
Pour the batter into the prepared pan(s) and bake until the cake springs back when touched and a tester inserted in the center comes out clean, about 45 minutes for a large bundt pan and about 20 minutes for mini-bundts. Cool in the pan for about 10 minutes, then invert the cake(s) onto a plate or wire rack and cool completely.
Melt the chocolate, butter, and corn syrup for 30-second intervals in the microwave, or over a bain-marie (double boiler) of low-simmering water. Let cool until slightly thickened, then spoon over the cake(s). Let the cakes with chocolate firm up before serving, about 30 minutes.