1. Preheat your oven to 300 degrees Fahrenheit (150 degrees Celsius). Prepare a bundt pan by generously spraying it with baking spray to prevent sticking.
2. In a medium bowl, sift together the all-purpose flour, baking powder, and salt. Set aside.
3. In a separate large mixing bowl, cream together the softened butter and sugar until light and fluffy.
4. Beat in the eggs, one at a time, ensuring each egg is fully incorporated before adding the next.
5. Mix in the sour cream, buttermilk, lemon juice, lemon zest, and vanilla extract until well combined.
6. Gradually add half of the sifted flour mixture into the butter mixture, mixing until just incorporated.
7. Pour in the buttermilk and then add the remaining half of the flour mixture, mixing until just combined. Be careful not to overmix; it’s okay if a few streaks of flour remain.
8. Pour the prepared cake batter into the prepared bundt pan, spreading it evenly.
9. Bake in the preheated oven for 60 to 70 minutes, or until a knife inserted into the center of the cake comes out clean.
10. Once baked, remove the cake from the oven and allow it to cool in the pan for 5 minutes.
11. Carefully invert the cake onto a cake platter or serving plate, allowing it to cool completely.

Lemon Glaze:

1. In a small bowl, cream together the softened butter and powdered sugar until smooth.
2. Slowly add in the lemon juice, continuing to beat until the glaze reaches a creamy, smooth consistency.
3. Spread half of the lemon glaze over the warm cake, allowing it to soak into the cake slightly.
4. Allow the cake to cool completely, then drizzle the remaining lemon glaze over the top.
5. Slice and serve your Italian Lemon Pound Cake, and enjoy the delightful citrus flavor with every bite!