Position a rack in the center of the oven and preheat to 325°F.
Cream 1 cup sugar and the butter in the bowl of a stand mixer fitted with the paddle attachment. (You can use a hand mixer if you allow the butter to soften at room temperature before beginning.) Paddle on low speed, then medium, for a total of 2-3 minutes. Add the eggs all at once, and paddle at low speed until blended, about 1 minute. Add the syrup and paddle for another minute; the mixture will be very wet, but that’s okay. Paddle on low speed for about 1 minute, then stop and scrape. Add the flour, paddle on low for 1 minute, then scrape. Paddle on low until thoroughly mixed; the mixture will still be very wet and look a little grainy.