processor with metal blade, ice cream scoop With a pencil, trace a 23 cm circle on each of 8 sheets of parchment paper (each one cut to fit a baking sheet). Preheat oven to 350 degrees. Combine butter and 1.5 cups of sugar in the bowl of an electric mixer fitted with a paddle. Beat the butter on low for 1 minute, on medium for 1 minute, and on high for 1 minute. Scrape down the sides of the bowl and beat on high for 1 additional minute. Once again, scrape down the bowl. Heat 3 cm of water in the bottom half of a double boiler over high heat. Place the egg whites in the top half of the double boiler and continuously whisk the whites while heating to a temperature of 110 degrees, about 1 minute. Slowly pour half of the beaten whites into the butter mixture while mixing on high, about 1 minute. Scrape down the bowl. Slowly add the remaining whites while mixing on high. Scrape down the bowl. Mix on high for 15 more seconds. Add the vanilla extract and beat on high for 5 seconds. Add the flour, mixing on low for 10 to 15 seconds, until the batter pulls away from the sides of the bowl. Remove the bowl from the mixer. Use a rubber spatula to finish mixing the batter, until it is smooth and thoroughly combined. Continued >>>