Place 3/4 cup of sugar and the corn syrup in a heavy-bottomed saucepan.  Do not stir.  Cook over medium-high heat to a dark caramel, swirling as it begins to brown to distribute the sugar.  Deglaze with the soy cream; then slowly add the soy milk.  The caramel will harden.  Bring to a boil, then simmer, stirring, just until the caramel has dissolved. 

In a large bowl, whisk together the remaining sugar, tofu, yogurt and fleur de sel.  Whisk a little caramel cream into the tofu mixture to temper it, then pour the tofu mixture into the remaining caramel cream and mix.  Strain the mixture through a fine-meshed sieve.  Cool completely, preferably overnight, then freeze in an ice cream maker.