Tunnel of Penuche Cake

Adjust oven rack to lower position and preheat oven to 350°F. Grease and flour bundt cake pan very thoroughly.

In bowl of stand mixer fitted with the paddle attachment, beat butter, brown sugar, and granulated sugar on medium speed until light and fluffy, about 2 minutes.

Add eggs one at a time, beating well after each addition. Beat in vanilla. Gradually add the two cups of confectioners' sugar until thoroughly blended.

Remove bowl from mixer and using wooden spoon, stir in flour, salt, and pecans until well blended. Spoon batter into greased and floured pan; spread evenly. Fill pan until batter reaches 1 inch from top of pan. Depending on the size of your bundt pan, you may have some extra batter.

Bake until top is set and edges are beginning to pull away from sides of the pan, 45 to 50 minutes. Cool upright in pan on wire rack 1 1/2 hours. Using a sharp knife, gently loosen the sides of the cake from the pan. Invert onto serving plate; cool at least 2 hours.

Once cooled, spoon butterscotch sauce on top of cake, allowing some to run down the sides. If desired, sprinkle chocolate shavings on top. Store tightly covered.