Here's a recipe from Cook's Illustrated that I couldn't resist. It's baking in my oven as I type this blog entry! Just one change makes it MSPI-friendly.
A note about margarine: I'm fortunate enough to have been able to locate an MSPI-friendly stick margarine (Fleischmann's Unsalted) that's perfect for baking. But not everyone is so lucky. Try talking to your grocery store about special ordering a case for you and throw it in your freezer. You could also try substituting shortening, but I believe when baking with shortening, you want to use a little bit less shortening than margarine or butter. Just experiment!
Easy Apple Snack Cake
2 cups all-purpose flour
1 tbsp. baking powder
1 tsp. ground cinnamon
1/2 tsp. allspice
1/4 tsp. ginger
1/4 tsp. table salt
1 cup packed light brown sugar
8 tbsp. unsalted margarine (butter), softened
2 large eggs, at room temperature
1/2 cup applesauce
1 tsp. grated lemon zest
2 Granny Smith apples, peeled, cored, and diced medium (2 cups)
1/2 cup raisins (optional)
Adjust an oven rack to the middle position and heat the oven to 325 degrees. Lightly coat an 8-inch-square cake pan with vegetable oil spray. Whisk the flour, baking powder, spices, and salt together in a large bowl and set aside.
Beat the brown sugar and butter together in a large bowl with an electric mixer on medium speed until light and fluffy, 3 to 6 minutes. Beat in the eggs, one at a time, until incorporated, scraping down the bowl and beaters as needed. Beat in the applesauce and lemon zest.
Whisk the flour mixture into the egg mixture until no streaks of flour remain. Stir in the apples and raisins (if using).
Pour the batter into the prepared pan and smooth the top. Bake until a wooden skewer inserted into the center of the cake comes out with a few crumbs attached, 1 hour to 1 hour and 15 minutes, rotating the pan halfway through baking.
Let the cake cool in the pan on a wire rack, about 2 hours, before serving.
To Make Ahead: After the cake has cooled, it can be wrapped tightly in plastic wrap and kept at room temperature for up to 3 days.