Spread the pecans out evenly on a baking sheet and toast in the oven for 5-8 minutes until fragrant. Set aside to cool.
Beat in the eggs, one at a time until fully incorporated, scraping down the sides of the bowl as necessary. Add the maple syrup, vanilla extract and continue beating until smooth.
In a small bowl of a food processor, add ½ cup of pecans and pulse gently until finely ground. Roughly chop the remaining pecans.
Fold in the chopped pecans. Pour the mixture into the prepared cake pan and top with the sliced pears, a few additional chopped pecans and sprinkle with demerara sugar if desired.