Preheat oven to 325°F (170°C).

In a large skillet, bring 1 cup (200 grams) sugar and cane syrup to a boil over medium-high heat; cook, stirring constantly, until sugar dissolves, about 2 minutes. Stir in 2 tablespoons (28 grams) butter until melted. Add apple and pear; reduce heat to medium, and cook, stirring occasionally, until fruit softens, about 12 minutes. Remove from heat, and let cool completely.

In the bowl of a stand mixer fitted with the paddle attachment, beat remaining 1½ cups (340 grams) butter and remaining 2 cups (400 grams) sugar at medium speed until fluffy, 3 to 4 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Beat in vanilla.

In a medium bowl, whisk together flour, cinnamon, salt, nutmeg, and baking soda. With mixer on low speed, gradually add flour mixture to butter mixture alternately with sour cream, beginning and ending with flour mixture, beating just until combined after each addition.

Reserve 2 tablespoons (36 grams) syrup from fruit mixture for Cane Syrup Glaze. Gently fold fruit mixture and remaining syrup into batter.

Spray a 15-cup Bundt pan with baking spray with flour. Spoon batter into prepared pan. Tap pan on a kitchen towel-lined counter a few times to settle batter and release any air bubbles.

Bake until a wooden pick inserted near center comes out clean, 1 hour to 1 hour and 10 minutes. Let cool in pan for 10 minutes. Loosen cake from center of pan using a small offset spatula. Invert cake onto a wire rack placed over a parchment paper-lined rimmed baking sheet, and let cool completely. Drizzle Cane Syrup Glaze onto cooled cake.