I want a single cake with a big dome coming out of a 4" deep 8" round pan but every recipe I've tried (madeira, etc) and strategy (whipping egg whites, creaming butter and sugar, cake flour vs all-purpose etc) don't get as big of a rounded dome top I'd like, they come out kinda flat.  My goal is something like in the pic below.  Anyone have any tips?  Thanks

https://www.odlums.ie/wp-content/uploads/2017/01/Madeira-Cake.jpg

I spent my entire caking life striving to achieve a perfectly FLAT top, so don't know what you need to do to get a high domed cake.  I would think additional leavening, baking powder or baking soda and a slightly higher temperature oven.  Those are just guesses!

To achieve this dome you have to have a sturdy batter, and you need to fill your cake pan more than half full. The cake will automatically rise above the cake pan, and should leave you with a substantial dome.

I could do it easy in a six inch pan and smaller -- I wouldn't want to try it in anything bigger myself -- not saying it's not possible just saying I wouldn't do it --  

but some ideas for you are to leave the pan of cake batter  sit out for fifteen minutes before placing in oven to let the baking powder get a head start --  bake at 350 to get the baking powder to it's favorite temperature -- after the cake firms up on top -- place a foil tent over it --

to get it to fully cook in the middle is tricky -- you don't want to lower the temperature too soon before the cake crust cracks open on top because that is how the last bit of batter makes it's escape and becomes cake but you need to start lowering the temp so the already baked part doesn't over bake -- so wait till it cracks before you start turning down the temp -- 

good luck