In a bowl, whisk together the cake mix, brownie mix, oil, and water. Add the eggs and whisk to incorporate.
Grease a bundt pan.
Pour the cake mixture into the pan and bake for 50-55 minutes or until a toothpick comes out clean.
For the Frosting
While the cake cooks, in a large bowl, whisk together the condensed milk and cocoa powder until homogeneous and smooth (without lumps of cocoa powder).
Add the butter and vanilla and whisk to incorporate.
Bring mixture to a non-stick saucepan over medium-low heat, stirring constantly until the mixture thickens and starts to peel away or reveals the bottom of the pan when you scrape it with a wooden spoon. Set aside.
Completing the Cake
Take the cake out of the oven and let cool in a rack for at least 1 hour.
On a working surface, still keeping it in the bundt pan, remove some of the cake filling to hollow it out, and reserve.
Fill the cavity with strawberries and evaporated milk. Cover with the shredded cake pieces and press firmly. Refrigerate for 20 minutes.