1. Preheat oven to 425 degrees. Put the butter in a 9 x 12 x 2 inch baking dish, preferably glass. Set the pan in the oven to melt butter. 2. Meanwhile, put eggs in blender and whirl at high speed for 1 minute. With motor running, gradually pour in milk, then slowly add flour. Continue whirling for 30 seconds. 3. When the butter in the pan is melted, remove the pan and pour batter into it. Return to oven and cook about 15-20 minutes, until golden and puffy. 4. Serve with powdered sugar and lemon juice, or/and syrup.