Old-fashioned Chocolate Cake With Cocoa Frost

• 1,000 gr powdered sugar
• 475 ml water (cold)
• 400 gr sugar
• 375 gr flour
• 350 gr semisweet chocolate chips
• 240 ml corn oil
• 45 gr unsweetened cocoa powder
• 14 gr vanilla
• 9 gr baking soda
• 6 gr butter (unsalted)