Preheat oven to 350F. Line a 9-in loaf pan with tin foil and lightly grease and flour. Set aside
In a large bowl with a handheld electric mixer, beat butter and sugar together until completely smooth and creamy. Beat in vanilla and and eggs one at a time, beating well after each addition. Slowly beat in 1/4 cup espresso, flour, baking powder, and salt until smooth.
Spread batter into prepared pan and smooth top. Bake pound cake at 350F 55-60 minutes or until toothpick tests done. Brush warm cake with remaining 1/4 cup brewed espresso.
Let cake cool in pan 20 minutes then invert onto a cooling rack to cool completely. Dust top of cake with powdered sugar then slice and enjoy!