Prepare the Peach Filling: Peel and slice the peaches into thin wedges or small chunks. Place them in a bowl and set them aside. For extra sweetness, sprinkle with a light dusting of sugar and let sit for a few minutes to draw out the juice.
Whip the Cream: In a mixing bowl, pour the cold heavy cream. Using a hand mixer or stand mixer, whip the cream until soft peaks form. Gradually add sugar and vanilla extract while continuing to whip until stiff peaks form. For extra creaminess, fold in the mascarpone cheese at this stage, if using.
Assemble the Dessert: In a serving dish, layer the peach slices, followed by the whipped cream. Repeat the layers until all ingredients are used, finishing with a layer of whipped cream on top. Garnish with crushed graham crackers and a dusting of cinnamon if desired.
Chill and Serve: Refrigerate for at least 2 hours to allow the dessert to set and the flavors to meld together. Serve chilled in individual portions or in a large serving dish.