1. Bloom the Gelatin: Begin by pouring the cold water into a small bowl. Sprinkle the powdered gelatin over the water and allow it to sit for 5-10 minutes. This step is essential because it “blooms” the gelatin, which means it absorbs the water and softens, making it easier to dissolve later. The gelatin will absorb the water and form a gel-like consistency, ensuring it can be easily mixed into the raspberry syrup later on.

2. Cook the Raspberry Mixture: In a medium saucepan, combine the raspberries, granulated sugar, and lemon juice. Set the heat to low and cook, stirring frequently. The sugar should dissolve completely into the raspberries, and the berries will release their juices. As the mixture warms, the raspberries will break down and become a lovely syrup. Once the sugar has dissolved, pass the mixture through a fine mesh strainer into a heatproof bowl. This will remove the seeds and leave you with a smooth, fruity syrup.

If you don’t have a fine mesh strainer, you can also use a cheesecloth or simply use a spoon to press the raspberry mixture against a sieve to extract the juices. The smoother the syrup, the smoother your mousse will be.

3. Dissolve the Gelatin: Return the strained raspberry syrup to the saucepan and add the bloomed gelatin. Warm the mixture over low heat, stirring occasionally, until the gelatin dissolves completely. Be sure not to let it come to a boil. If the syrup gets too hot, it may cause the gelatin to lose its setting power, which can result in a mousse that doesn’t firm up properly. Once the gelatin is dissolved, remove the saucepan from the heat, pour the syrup into a clean, large bowl, and set aside to cool.

It’s important to let the syrup cool to room temperature before proceeding. If the syrup is too warm when mixed with the whipped cream, it may cause the cream to deflate, resulting in a mousse that’s less airy.

4. Whip the Cream: In a separate mixing bowl, beat the heavy whipping cream and powdered sugar together. Start on low speed to prevent splattering, and gradually increase to medium speed. Continue whipping until soft peaks form. Soft peaks are when the cream holds a shape but falls over when the beaters are lifted. Then, turn the speed up to medium-high and whip until stiff peaks form. Stiff peaks hold their shape and stand upright when the beaters are lifted. This step is crucial—stiff peaks ensure that your mousse will hold its shape and have that lovely light, airy texture.

If you’re unsure about stiff peaks, just take a look at the whipped cream’s consistency. You should be able to lift the beaters out of the cream and have the peaks stand up straight without collapsing. Overwhipping will cause the cream to become too thick and buttery, so be cautious to stop at the right moment.

5. Combine the Raspberry Syrup and Whipped Cream: Once the raspberry syrup has cooled to room temperature but is still slightly warm, add 1/4 of the whipped cream to the mixture. Gently fold it in with a spatula until well combined. This helps lighten the syrup before you add the rest of the whipped cream. Then, gently fold in the remaining whipped cream until no white streaks remain. Be careful not to overmix, as you want to maintain the airy texture of the mousse. The goal is to create a smooth, light, and fluffy texture without deflating the whipped cream.

Remember, folding is a technique where you gently mix the ingredients using a spatula or spoon, turning the bowl as you go. This method helps preserve the air incorporated into the whipped cream, ensuring your mousse has the light texture you’re aiming for.

6. Set the Mousse: Divide the mousse mixture evenly between 4-6 individual serving dishes. Cover them with plastic wrap or a lid and refrigerate for at least 2 hours. During this time, the mousse will firm up and set, creating a light, airy texture that’s simply irresistible. If you’re in a hurry, you can chill the mousse in the freezer for about 30 minutes to speed up the process, but for the best results, allow the mousse to set in the refrigerator.

7. Garnish and Serve: Once the mousse is set, garnish each serving with fresh raspberries and a dollop of extra whipped cream for a finishing touch. The added berries not only enhance the look of the mousse but also give it a fresh burst of flavor with every bite. Serve and enjoy! The mousse should have a silky texture that gently melts in your mouth, with the bright and tangy flavor of the raspberries shining through.