Preheat oven to 350 degrees with a rack in the middle. Spray one 8 inch-by-3 inch cake pan with nonstick cooking spray; set aside.
Place dates and 1/2 cup water in a small saucepan. Bring to a boil and immediately reduce heat to a simmer; simmer until water is almost evaporated. Transfer dates to the bowl of a food processor; pulse until coarsely chopped. Set aside.
In a medium bowl, whisk together flour, baking powder, salt, baking soda, nutmeg, and cloves.
In the bowl of an electric mixer fitted with the paddle attachment, beat butter and brown sugar on medium speed until light and fluffy, about 4 minutes. Add eggs, and beat until combined, scraping down sides of bowl as necessary. Add molasses, maple syrup, vanilla, and date mixture; beat to combine. With the mixer on low speed, add the flour mixture. Mix until just combined.
Pour 1/2 cup maple toffee sauce into bottom of prepared cake pan; sprinkle with pecans. Pour batter into cake pan, smooth top, and transfer to oven. Bake until deep golden and a cake tester inserted into the center comes out clean, about 55 minutes.
Remove pudding from oven and let cool for 10 minutes. Run a small offset spatula around edge of cake pan and invert pudding onto serving platter. Immediately pour additional maple toffee sauce over cake; let cool slightly. Serve warm with whipped cream.