Preheat oven to 325°F. Position a rack in the center. Grease and flour a 10-inch Bundt pan or spray it with baking spray that contains flour.

In a large mixing bowl, use an electric mixer to beat 1 cup softened salted butter, 1/2 cup creamy peanut butter, 1 cup granulated sugar, and 1 cup packed light brown sugar until light and creamy, about 5 to 7 minutes.

Add the 5 large eggs one at a time, beating well after each addition and scraping down the sides of the bowl as needed.

Beat in 1 tablespoon vanilla extract until combined.

In a medium bowl, whisk together 3 cups all-purpose flour, 1/2 teaspoon salt, 1/2 teaspoon baking powder, and 1/4 teaspoon baking soda.

With the mixer on low, add the flour mixture to the batter in three additions, alternating with the 1 cup milk (beginning and ending with the flour). Beat just until each addition is incorporated; do not overmix.

Fold 1 cup mini chocolate chips into the batter with a rubber spatula until evenly distributed.

Transfer the batter to the prepared Bundt pan, smoothing the top. Bake for 60 to 70 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool the cake in the pan on a wire rack for 10 minutes. Invert the cake onto the rack or a serving platter and let it cool completely before frosting.

To make the icing, beat 1/4 cup softened salted butter and 1/4 cup creamy peanut butter together until smooth.

Add 2 cups confectioners' sugar and 1 tablespoon milk and beat until smooth. Add additional milk, 1 tablespoon at a time (using a total of 3 to 4 tablespoons if needed), until the frosting is thin enough to spread.

Spread the frosting evenly over the completely cooled cake. Allow the frosting to set briefly before slicing and serving.