In a small saucepan, sprinkle gelatin over 3 tablespoons cold water. Let stand until softened, about 5 minutes. Heat over low, stirring, until gelatin has dissolved, about 30 seconds.

In a large bowl, whisk 1/4 cup sugar with buttermilk until dissolved. Whisking constantly, add gelatin mixture in a very thin stream. In another large bowl, beat cream and 1/4 cup sugar until soft peaks form.

With a rubber spatula, gently stir half of whipped cream into buttermilk mixture; fold in remaining whipped cream. Divide among eight 6-ounce ramekins. Refrigerate until set, at least 6 hours (or up to 1 day, covered with plastic wrap).

When ready to serve, toss strawberries with 1/4 cup sugar, lemon juice, and 1 tablespoon water. Let stand until juicy, about 5 minutes. Run a paring knife around edge of each ramekin and dip each briefly in steaming hot water; invert buttermilk creams onto serving plates and top with strawberries.