Prepare the chocolate cake first; this can be done even a few days in advance. Preheat the oven to 350F and line the bottom of an 8-inch pan with parchment paper (see my note above about using a larger pan).
In a large mixing bowl, cream together the softened butter and sugar for a few minutes until light and fluffy. Then add in the eggs and vanilla extract. Mix again until creamy. Combine the milk and instant coffee, then heat until the coffee dissolves and milk is warm. Pour the milk into the batter.
In a separate bowl, combine all the dry ingredients: flour, cocoa powder, salt and baking powder. Mix together, then sift into the cake batter to get rid of any clumps. Using a hand whisk, mix the flour into the batter just until combined. Be careful not to over-mix the batter! Gently fold in melted chocolate at the very end. Bake the batter in the prepared pan for 40 to 45 minutes, until a toothpick inserted into the center comes out clean. Allow the cake to cool completely, then level off the top and split the layer in half.
Prepare the chocolate cake for filling. Spread 1/4 cup strawberry preserves onto each layer. Place one layer into the bottom of a spring form pan and line the sides with acetate. Arrange the large, sliced strawberries along the perimeter of the pan, with the open side facing out.
For the cheesecake filling: place the softened cream cheese, ricotta cheese, sweetened condensed milk and vanilla into a large mixing bowl. Whisk on high speed for 3 to 4 minutes, scraping down the sides of the bowl often, until the mixture is creamy and clump free. Add the confectioner's sugar and heavy cream. Mix on low speed for a minute, then increase speed and whisk until mixture is fluffy, about 2 minutes on high speed.
Next, prepare the gelatin (see my notes on using agar above). Combine the gelatin and 1/4 cup water in a small bowl and mix together well. Microwave for 45 seconds, stirring every 10 seconds, until the gelatin is completely dissolved. Do not allow the gelatin to cool; add it straight into the cheesecake filling and whisk right away on high speed. Scrape down the bowl to make sure it's all incorporated.
Fold in the diced strawberries last, then pour the filling into the prepared spring form pan. Level off the top of the cheesecake, then place the second chocolate cake layer on top. Press it lightly in place. Refrigerate the cake for at least 6 hours, or leave it in the fridge overnight.
When ready to serve, garnish with whipped cream and strawberries. For the whipped cream, place the chilled heavy cream, sugar and vanilla into a large mixing bowl. Whisk on high speed for 4 to 5 minutes, until stiff peaks form. Pipe onto the cake using a decorative tip; I used # 829.