Preheat the oven to 250 degrees. Butter an 8-by-2-inch round cake pan, line the bottom with a round of parchment paper, and butter the parchment paper; set aside.
Blanch peppercorns in a small saucepan of boiling water for 1 minute; drain. Repeat two more times. Pat peppercorns dry with paper towels
Spread peppercorns evenly in a small baking pan. Transfer to oven until thoroughly dry, 15 to 20 minutes. Remove from the oven, and let cool. Increase the oven temperature to 350 degrees.
In a spice grinder or with a mortar and pestle, grind peppercorns to medium-fine; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, beat cream cheese and sugar on medium-high speed until very smooth, about 3 minutes. Scrape seeds from vanilla bean, and add to the cream cheese mixture with reserved pepper. Reserve the pod for another use. Beat in creme fraiche and lemon juice. Scrape down the sides of the bowl. Add eggs, one at a time, beating well after each addition, and scraping down the sides of the bowl as necessary. Beat in cream.
Pour batter into the prepared pan. Place the pan in a large roasting pan. Add enough hot water to come 1 inch up the sides of the roasting pan. Bake until edges are set and center shivers slightly when shaken, about 1 1/4 to 1 1/2 hours. Remove the cake pan from the roasting pan, and transfer to a wire rack to cool completely.
When cool, cover with plastic wrap and refrigerate overnight.
To unmold cheesecake, run a thin knife or spatula around the edges to loosen. Then carefully place the pan over a hot burner, shaking gently from side to side, for about 20 seconds. Invert the cake onto a serving plate, peel off parchment paper, and serve with pineapple, if desired.