Peel and cut Kiwi and Mango into small square cubes. Slice Strawberries into half.
In a cold bowl, add the heavy cream, sweetened condensed milk, and vanilla extract, and whip until firm peaks form.
Spread an even layer of whipped cream on 4 slices of bread and top it with the fruit. Top the fruit with an even layer of cream. Cover the sandwiches with the remaining four slices of bread, and then remove the crusts.
Refrigerate the sandwiches for at least 1 hour. Slice them into halves or quarters while serving.