From Jennifer Steinhauer of The New York Times.
2 cups unsalted butter, at room temperature, plus more to grease the pans
3 cups granulated sugar
6 large eggs, at room temperature
2 teaspoons vanilla extract
1 teaspoon salt
3 cups cake flour
¼ cup heavy cream
Heat the oven to 325°F. Generously butter and flour 12-cup bundt pan or two 8.5-inch-by-4.5-inch loaf pans, and set aside.
Using an electric mixer or by hand, cream together the remaining butter and sugar. Add the eggs one at a time, beating well after each addition. Beat in the vanilla and salt.
Gently stir in the flour by hand, adding it very gradually; this will help to keep the cake tender. Add the cream and stir just until thoroughly combined.
Pour the batter into the pan or pans and smooth the top. Bake until a toothpick inserted in the center comes out clean, about 1 hour and 15 minutes. Cool in the pan for 10 minutes, then turn the cake out onto a rack to cool completely.
Note: from Cathy Barrow, how to ensure that your bundt pan releases the cake: Combine the 1 tablespoon of shortening and 1 tablespoon of flour in a small bowl. Use your fingers or a paper towel to generously coat the inside of the bundt pan with the paste, systematically working it into each crevice. Aim to evenly cover all the surfaces, including the center tube and the uppermost edges, because the baked cake will fill the entire pan. Get rid of any excess paste.