Preheat the oven to 350°F (175°C). Line a 9" springform pan with parchment paper (or use an equivalent pan with at least 2" tallsides).
Thinly slice one of the peaches - about 15 to 20 pieces. Keep the pieces about 1/4 " thick or less to prevent them from sinking into the batter. Cut the remaining peaches into small cubes about 1/2 cm thick (about 2 cups).Add 2 Tbsp of the cake mix to the cubed pieces and toss to coat. Set aside.
Beat water, eggs and oil together until well mixed and a little frothy. Slowly beat in half the cake mix and fold in the rest by hand. Make sure that there are no large lumps. Add the cubed peaches and fold in using a spatula.
Transfer the batter into the prepared pan. Arrange the sliced peaches on top, in any decorative manner. Do not cover the top fully, leave some room for the cake batter to expand.
Bake in the preheated oven for 45 to 50 minutes, until the tops have browned lightly and a toothpick inserted in the center comes out clean .
Remove from the oven and let cool for 5 minutes in the pan.
Transfer to a cooling rack and take the ring off the spring form pan. Cool completely before slicing .
Using a different kind of pan will change the baking time.
If using a large pan check the cake after 30 minutes, if browning too fast tent with aluminum foil and reduce the heat to 325°F (160°C).
Check the blog for home made cake mix recipe.
For detailed instructions go to https://oventales.com/fresh-peach-coffee-cake/ .