Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan. In a large mixing bowl, sift together the flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt until well combined. In a separate bowl, whisk together the eggs, buttermilk, hot water, oil, and vanilla extract until smooth. Gradually pour the wet ingredients into the dry, mixing until just combined, then pour the batter into the prepared pan.

Place the cake in the preheated oven and bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean. Keep an eye on it to ensure it doesn't overbake; the edges should pull slightly away from the pan while the center remains moist. Once done, remove the cake from the oven and let it cool completely in the pan on a wire rack.

Once the cake has fully cooled, use the handle of a wooden spoon to poke holes evenly across the surface of the cake, about 1 inch apart. In a saucepan over low heat, combine the smooth peanut butter, sweetened condensed milk, and whole milk, stirring until the mixture is smooth and warm. Pour this luscious glaze over the cake, ensuring it seeps into the holes for maximum flavor.

In a chilled mixing bowl, pour in the heavy whipping cream and whip using an electric mixer on medium speed until soft peaks begin to form. Gradually add in the sifted powdered sugar and peanut butter, continuing to whip until stiff peaks form, which should take 2–3 minutes. Once ready, gently spread the light and fluffy whipped cream over the top of the glazed cake for a creamy finish.

To add a touch of flair to your Chocolate Peanut Butter Poke Cake, garnish with chopped chocolate peanut butter cups and a sprinkle of crushed peanuts if desired. Serve chilled or at room temperature, slicing into squares to reveal the moist layers within.