To make the cake:

• Preheat the oven to 350°F. Lightly grease an 8 by 8 inch cake pan with butter and dust lightly with flour.
• Sift flour, cinnamon, cloves, white pepper, ground ginger and baking soda into a bowl. Set aside.
• In the bowl of a stand mixer, combine grated ginger, 1/2 tablespoon water, sugar, oil and molasses. Mix on low speed. Add eggs and continue mixing on low until completely combined.
• Slowly add dry ingredients to wet ingredients, continuing to mix on low, scraping down the sides of the mixing bowl when needed. Once all dry ingredients are slightly incorporated, increase speed to medium and mix for 2 minutes. Scrape down the sides, decrease speed to low and slowly add 3/4 cup hot tap water. Mix until just combined, scraping down the sides one last time.
• Pour mixture into the prepared cake pan. Bake until a toothpick inserted into the center of the cake comes out clean (40 - 45 minutes).

To make the salted caramel sauce:

• While the cake is baking, prepare your sauce. In a medium sized pot (with high walls), combine sugar and 1 3/4 cups hot water, stirring until the sugar dissolves. Stir in corn syrup and cream of tartar. Bring mixture to a boil over high heat and place a lid on the pot (preferably a lid you can see through). This will prevent sugar crystals from forming on the sides of your pot. Do not stir. Cook mixture until it reaches a deep caramel color and a candy thermometer reaches 335°F.*
• Remove the pot from the heat and slowly and carefully stream in the heavy cream, stirring to incorporate (a high walled pot should keep you safe from any splattering). Stir in kosher salt and butter, one tablespoon at a time. The finished caramel sauce will be a little thin. If you want to thicken the sauce before serving, transfer sauce to a bowl or small pitcher and cool in the refrigerator for 5 - 10 minutes (but not too long!).

To serve, spoon some of the caramel sauce on a plate or shallow bowl. Place a square of ginger cake in the middle of the sauce. Finish with a dollop of freshly whipped cream.