Marble Pound Cake like from NYC food carts?

Hey everyone! I was wondering if anyone knew how to make a good marble pound cake like the ones sold at NYC food/pastry carts? There used to be a food cart by my house that had the best marble pound cake known to man and I've been chasing that for years. Recently got one of Costco's all-butter pound cakes and found it was too light and fluffy. The food carts' pound cake I remember is super dense and the right balance or moist but not too oily. If anyone knew what I was talking about and had any tips for recreating that taste I'd be most appreciative!