If you have a good mixer, you're ready to make these meringues in no time.
Make meringues: Line a plate with plastic wrap; set aside. In a large bowl, using an electric mixer, beat egg whites and vanilla on medium-high speed until mixture forms soft peaks that fall back when lifted with beater. With mixer running, add 1/3 cup sugar, about 1 tablespoon at a time; continue to beat until mixture forms stiff peaks when lifted with beater. Using a rubber spatula, divide egg-white mixture into quarters in mixing bowl.
Poach meringues: Fill a large skillet with 1 inch of water. Over high heat, bring to a simmer. Reduce heat to medium-low so water is steaming but not simmering. Dip a large slotted spoon in cool water, then scoop up 1/4 egg-white mixture, and with a rubber spatula, round top and slide meringue off spoon into skillet. Repeat with remaining meringues. Poach 4 minutes on one side. Flip over with slotted spoon, and poach meringues until firm to the touch, about 3 minutes. Using slotted spoon, transfer to prepared plate. Cover with another sheet of plastic, sealing around the edge of plate, and refrigerate at least 15 minutes and up to 1 day.
Make sauce: Meanwhile, in a blender, combine raspberries and remaining 3 tablespoons sugar. Blend on high speed until smooth. Pour mixture through a fine-mesh sieve, pressing with rubber spatula; discard seeds. (If making ahead, cover and refrigerate up to 2 days.) To serve, divide sauce among 4 serving plates, top with a meringue, and sprinkle with almonds.
A wet slotted spoon transfers these delicate treats easily; round tops with a spatula to give them uniform shape. Lining the plate of meringues with plastic wrap and then covering tightly with more wrap is a good way to keep them soft.