Beat the softened butter for 20 seconds in a large mixing bowl with an electric mixer or a stand mixer with the paddle attachment.
Add the sugar gradually while you continue beating at medium speed, and then for 3 more minutes at high speed after adding all of it. The mixture should be light in color and fluffy.
Add the eggs, one at a time, beating well after each addition. Make sure to scrape the sides of the bowl regularly.
Add vanilla extract and mix.
Sift the dry ingredients (flour, salt, and baking powder) together in a medium bowl, or have them measured and sift them directly over the butter mixture.
Add the flour mixture in 2 parts, alternating with the cream cheese in 1 part. That means you start and end with the dry ingredients.
Mix and integrate everything well, but don't beat much at this point. After adding flour, a cake batter should not be beaten too much or it will develop gluten and toughen the baked cake.
Put the cake batter in the prepared pan and smooth the top.
Add the sliced peaches, overlapping them and covering the batter. It might look like too many peaches but it's not.
Drop teaspoons of the topping mixture (instructions below) on top of the peaches. Lightly spread the mounds but don't cover the whole thing. There should be space for the cake to grow.
Sprinkle with the extra teaspoon of sugar.
Bake for about 45 minutes, until it rises, the topping dries, and a cake tester or toothpick inserted in the middle comes out clean. Pound cakes are dense so make sure it's fully baked. If the top is browning too quickly but the middle is not done, cover it loosely with a piece of aluminum paper and continue baking.
Cool on a wire rack and remove carefully from the pan, removing the strip of paper.