Place the pear halves in a small saucepan. Sprinkle with 2 tablespoons sugar and drizzle with the lemon juice. Add water until the pears are just submerged. Simmer for approximately 5 minutes, until pears are just tender but not mushy. Remove from poaching liquid and allow to cool. When cool, slice the pears lengthwise into 1/4-inch slices.
Preheat oven to 350°F. Butter an 8-by 2-inch round cake pan and line the bottom with parchment paper. Set aside.
Melt the chocolate and butter, together, over a water bath or in the microwave.
In a small bowl, combine all the dry ingredients. Whisk together and set aside.
In the bowl of a stand mixer, beat the eggs and sugar until light and pale in color. Stir in the vanilla, then the melted chocolate/butter and the flour mixtures, until just combined.
Pour the batter into the prepared pan and arrange the sliced pears on top. Sprinkle with the fresh cranberries and the crystal sugar. Place the cake in the oven and bake for approximately 25 minutes, or until the middle is just set.
Remove from the oven and let cool completely. Run a knife or small spatula around the edge of the pan and invert onto a plate. Flip again onto a serving platter so the pears and cranberries are facing up. Serve with softly whipped cream or crème fraiche.
Recipe courtesy of Heather Hardcastle of Flour Craft Bakery