Position rack in center of oven and preheat to 325°F Butter and flour standard Bundt pan, then spray pan with nonstick spray. Pour bourbon into small bowl. Scrape seeds from vanilla bean into bourbon; stir to blend well (reserve scraped vanilla bean for another use).
Whisk flour, baking powder, and salt in medium bowl to blend. Using electric mixer, beat butter and both sugars in large bowl until light and fluffy. Add eggs and egg yolk 1 at a time, beating until well blended after each addition. Beat in bourbon-vanilla mixture. Add flour mixture in 2 additions alternately with buttermilk in 1 addition, beating just until blended after each addition. Transfer batter to prepared pan; smooth top evenly (batter will come only halfway up sides of pan).
Bake cake until tester inserted near center comes out clean, about 55 minutes. Cool in pan on rack 15 minutes. Invert cake onto rack and cool completely.
Whisk powdered sugar, 4 teaspoons milk, and vanilla in small bowl to blend, adding more milk by 1/4 teaspoonfuls if glaze is too thick to drizzle.
Place sheet of foil on work surface. Place cake (still on rack) atop foil. Using spoon, drizzle glaze over cake in zigzag pattern. Let cake stand at room temperature until glaze sets, about 15 minutes. DO AHEAD Cake can be made up to 1 day ahead. Cover with cake dome and let stand at room temperature.
Toss strawberries and sugar in medium bowl. Let stand at room temperature until juices form, tossing occasionally, about 30 minutes.
Cut cake into wedges and divide among plates. Spoon strawberries with juices alongside and serve.