Adapted from Baking From My Home to Yours.
1/2 cup all-purpose flour
1/8 teaspoon salt
1/8 teaspoon cinnamon
1/3 cup oatmeal
3/4 cup butterscotch chips
1-1/2 sticks butter, at room temperature and cut into 12 pieces
3 large eggs, at room temperature (I used All Whites)
1/2 cup Splenda Sugar Blend
Getting ready: Center a rack in the oven and preheat the oven to 300°F. Line an 8-inch square baking pan with non stick foil.
Whisk together the flour, salt and cinnamon.
Put the butterscotch in a heatproof bowl and set the bowl over a saucepan of simmering water. Slowly and gently melt the butterscotch, stirring occasionally. Remove the bowl from the saucepan and add the butter, stirring so that it melts. It's important that the butterscotch and butter not get very hot. However, if the butter is not melting, you can put the bowl back over the still-hot water for a minute. If you've got a couple of little bits of unmelted butter, leave them—it's better to have a few bits than to overheat the whole. Set the butterscotch aside for the moment.
Working with a stand mixer with the whisk attachment, or with a hand mixer in a large bowl, beat the eggs and Splenda sugar blend until they are thick and pale, about 2 minutes. Lower the mixer speed and pour in the butterscotch-butter, mixing only until it is incorporated—you'll have a thick, creamy batter. Add the dry ingredients and mix at low speed for about 30 seconds—the dry ingredients won't be completely incorporated and that's fine. Finish folding in the dry ingredients by hand with a rubber spatula, then fold in the oatmeal.
Scrape the batter into the pan and bake 50 to 60 minutes, or until a knife inserted into the center of the cake comes out clean. Transfer the pan to a rack and allow the tannies to cool to warm or room temperature.
Carefully lift the tannies out of the pan, using the foil edges as handles, and transfer to a cutting board. With a long-bladed knife, cut the tannies into 16 squares, each roughly 2 inches on a side, taking care not to cut through the foil.
Storing: Wrapped well, these can be kept at room temperature for up to 3 days or frozen for up to 2 months.