For The Cake, Place A Rack In The Center Of The Oven, And Preheat The Oven To 350°F.
Lightly Grease As Many 9″ Round Layer Pans As You Have (You Need 10 Layers) With Soft Butter Or Oil.
Set The Pans Aside.
(Or Buy Ten 9″ Round Aluminum Foil Pans To Save Time. )
Place The Butter And Sugar In A Large Mixing Bowl, And Beat With An Electric Mixer On Medium Speed Until Light And Creamy, 1 Minute.
Add The Eggs, One At A Time, Beating On Medium Until Just Combined.
Set Aside.
Sift The Flour, Baking Powder, And Salt Into A Medium-Size Bowl.
Add The Flour Mixture To The Butter And Sugar Mixture Alternately With The Evaporated Milk.
Begin And End With The Flour Mixture.
Beat On Low Speed Until Smooth, About 1 Minute.
Scrape Down The Sides Of The Bowl, And Fold In The Vanilla.
Spoon About A Generous ½ Cup Batter Into Each Prepared Pan, Using The Back Of A Large Spoon To Spread The Batter Across The Bottom Of The Pan.
Place Up To 3 Pans In The Oven At A Time, Or Place In As Many Layers As Your Oven Will Accommodate.
Bake Until The Top Of The Cake Springs Back When Lightly Touched With A Finger, 14 To 17 Minutes.
Remove The Cakes From The Oven, Let Them Rest In The Pans For 5 Minutes, Then Carefully Remove To A Wire Rack To Cool.
Repeat The Process With The Remaining Batter And Layers.
Once All The Layers Have Baked And Are Cooled, Prepare The Frosting.
Melt The Butter In A Large Saucepan Over Low Heat, 2 To 3 Minutes.
Stir In The Cocoa, Salt, And Evaporated Milk.
Cook And Stir Until The Mixture Thickens And Just Begins To Come To A Boil, 1 Minute Longer.
Remove The Pan From The Heat.
Stir In The Vanilla And The Confectioners’ Sugar, Continuing To Stir Until The Frosting Is Thickened And Smooth And The Consistency Of Hot Fudge Sauce.
To Keep The Frosting From Hardening, Place The Saucepan Over Low Heat While Frosting The Layers.
To Assemble The Cake, Place 1 Layer On A Cake Plate And Spoon About ¼ Cup Of The Frosting On Top, Spreading It Thinly To The Edge.
Place Another Layer On Top, And Continue Adding ¼ Cup Of Frosting And Stacking The Layers.
When All The Layers Have Been Stacked, Frost The Top And Sides Of The Cake Thinly With The Remaining Frosting.
Store This Cake At Room Temperature Under A Cake Dome Or In A Cake Saver For Up To 3 Days.
It Will Keep 1 Week In The Refrigerator.
Chocolate Peanut Butter Option: Chop 3 Frozen Peanut Butter Cups Into Chunks And Set Aside As The Garnish For The Top Of The Cake.
Pulse The Remaining 5 Peanut Butter Cups Into A Fine Powder In The Food Processor.
As You Are Stacking The Cake Layers, Scatter 2 Teaspoons Peanut Butter Cup Powder On Top Of Each Frosted Layer.
Once Finished, Garnish The Top Of The Cake With The Reserved Peanut Butter Cup Chunks.
