Preheat oven to 425ºF.
In a small bowl, combine the sugar, cornstarch and cinnamon.
In a large bowl add the raspberries and lemon juice and toss to combine.
Add the sugar mixture and toss to coat.
Divide the raspberry mixture between 6 ramekins.
Top with small pieces of butter.
Bake in preheated oven for 35-40 minutes.
Remove from the oven and allow to cool completely.
To make the whipped cream, add the heavy cream and sugar to a bowl and beat until stiff peaks form.
Top the mini pies with whipped cream and serve.