Mix the flour, baking powder and salt together in a small bowl. Using an electric mixer, cream the butter and sugar together until light and fluffy, 3-5 minutes. Then add the vanilla.
Crack the eggs into a measuring pitcher. Then with the mixer running, alternate adding the eggs and flour mixture until just combined. Scrape the bowl and mix again for 30 seconds.
Divide the cake batter evenly between the two pans and bake for 20 minutes, until golden on top. Remove the cakes from pans and cool for 20 minutes. Meanwhile, whisk the evaporated milk, condensed milk and cream together. Set aside.
Once the cakes are cool, place one on a cake platter and the other on a sheet of foil with the edges turned up to form a shallow bowl. Poke both cakes with a fork thoroughly, to help the milks absorb. Slowly pour half the tres leches mixture over each cake and allow them to sit and soak it all up while you make the Mango Cream.
For the Mango Cream:
Peel both mangoes. Slice one into thin strips and set aside as the garnish. Cut the second off the pit and place in the blender with 2/3 cup sugar and a pinch of salt. Puree until smooth.
Pour the puree into a small sauce pan and place over medium-high heat. Bring to a simmer. Stir and simmer for 3-5 minutes until thick. Then place in the fridge to cool.
Using a clean bowl and electric mixer, whip the heavy cream until firm peaks form. Then gently fold in the chilled mango puree.
Scoop about half the Mango Cream on the cake that's on the platter. Spread the Mango Cream evenly, then carefully flip the second cake layer on top and remove the foil. Spread the remaining mango cream on the top and decorate with fresh mango slices.