Prepare the sweet potatoes by scrubbing them clean, pricking them all over with a fork, and placing them on a foil-lined baking sheet. Bake them in an oven preheated to 450°F for about 1 hour or until they can easily be pierced with a fork. Allow the sweet potatoes to cool enough to handle.
Lower your oven temperature to 375°F. Spray or butter a 9x13 baking dish and set it aside.
Peel the sweet potatoes and add them to a large mixing bowl. Use the beaters of an electric handheld mixer (with the mixer turned off) or a fork to break the sweet potatoes apart. Add the softened butter and beat the sweet potato mixture on medium-high with the handheld mixer for 2-3 minutes until light and fluffy.
Add the brown sugar, maple syrup, vanilla, cinnamon, nutmeg, cloves, salt, and eggs to the bowl with the sweet potatoes and beat on medium-high until well combined. Pour the mixture into the prepared baking dish, smooth it out into an even layer, and set it aside.
Add the pecans, brown sugar, flour, salt, and ground cinnamon to a small mixing bowl and mix with a fork until combined. Pour in the melted butter and continue mixing until a crumbly texture is reached.
Spoon the streusel topping over the sweet potato mixture in an even layer. Bake the casserole in the preheated oven for 35-45 minutes or until the casserole is golden brown and bubbly. Allow the casserole to cool for about 10 minutes then serve warm.