In a medium mixing bowl, combine the digestive biscuit crumbs with the melted butter. Mix thoroughly until the mixture resembles wet sand and holds together when squeezed in your hand.
Press the crumb mixture firmly and evenly into the bottom of a 9-inch springform pan. Use the back of a measuring cup or your fingers to pack it down tightly for a stable crust. Once done, place the crust in the refrigerator to firm up while you prepare the filling.
In a large mixing bowl, beat the softened cream cheese with an electric mixer on medium speed until creamy and smooth. Gradually add in the powdered sugar and vanilla extract, continuing to mix until fully incorporated and without lumps.
In a separate bowl, using a clean mixer or whisk, whip the chilled heavy cream until soft peaks begin to form. This process usually takes about 2-3 minutes. Be cautious not to over-whip.
Carefully fold the whipped cream into the creamy cheese mixture, using a rubber spatula. Gently incorporate until well blended, taking care to maintain the light and airy texture.
Gently fold the sliced strawberries into the cheesecake filling, reserving a few slices for garnishing later. Pour this delightful mixture into the prepared crust, smoothing the top with a spatula for an even finish.
Cover the springform pan tightly with plastic wrap and place it in the refrigerator to chill for at least 4 hours, or overnight for optimal setting.
When the cheesecake is set, gently heat the strawberry jam in a small saucepan over low heat until it becomes pourable. Drizzle the warmed jam over the cheesecake and artfully arrange the reserved strawberry slices on top for an attractive presentation.
Carefully unlock and remove the sides of the springform pan to reveal the cheesecake. Slice into wedges and serve chilled, garnished with fresh mint leaves if desired.