Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
In a large bowl, cream together the butter (ing_5) and sugar (ing_4) until light and fluffy. Beat in eggs (ing_6) one at a time, then stir in the vanilla (ing_7).
In a separate bowl, whisk together the flour (ing_1), baking powder (ing_2), and salt (ing_3). Gradually add to the wet ingredients, alternating with the milk (ing_8), beginning and ending with the dry ingredients.
In a medium bowl, combine the diced peaches (ing_9), sugar (ing_10), cornstarch (ing_11), and lemon juice (ing_12). Mix well.
Pour half of the pound cake batter into the prepared pan. Spread the peach filling evenly over the batter. Top with the remaining pound cake batter.
Bake for 40-45 minutes, or until a wooden skewer inserted into the center comes out clean.
While the cake is baking, whisk together the powdered sugar (ing_13), heavy cream (ing_14), and vanilla extract (ing_15) to make the glaze.
Once the cake is cool, pour the glaze over the top and let it set before cutting into individual "Twinkies".
Notes
For a richer flavor, use brown sugar instead of granulated sugar in the pound cake.