The golden-brown exterior camouflages thehidden treasure -- a ring of pecan streuselsuspended in a melt-in-your-mouth butterycakeenriched by the addition of tangy sour cream.
Preheat oven to 350 degrees. Sift together flour, baking soda, baking powder, and salt into a bowl; set aside. Butter a 10-inch Bundt pan (or other tube pan with 3-quart capacity); set aside.
In the bowl of an electric mixer fitted with the paddle attachment, cream butter and granulated sugar until light and fluffy, about 4 minutes. Add eggs, one at a time, until well combined. Add vanilla; stir until combined. Add the reserved flour mixture and sour cream, and stir just until well combined. Spoon half the batter into the bottom of the prepared pan. Make a well in the batter, and crumble 2/3 of the streusel mixture into the well. Top with remaining batter, smoothing top. Sprinkle remaining streusel evenly over the top. Bake until golden brown and a cake tester comes out clean, about 1 hour.
In a medium bowl, whisk together the confectioners' sugar and milk until well combined; set aside, covered with plastic wrap, until ready to use. Cool cake until just warm before drizzling with icing.