Instructions

Make the Caramel (skip if using store-bought)

1. In a heavy-bottomed saucepan, add the white granulated sugar and water, swirling gently to make sure the sugar is coated. Add the pan to medium-high heat and bring to a boil.
2. Meanwhile, set up a hot pad holder or folded towel next to your stove. Get a wooden/bamboo utensil (like a large spoon or long chopstick) ready. Combine the oat milk and vanilla extract and set the mixture near the hot pad holder.
3. Once the sugar water begins to boil, keep an eye on it until it reaches a dark amber color. It will take a while for the sugar to turn from clear to amber, but once it begins to color, it can burn quickly - so keep an eye on it!
4. When the sugar turns a dark amber color, immediately remove it from the heat and place on your hot pad holder. While stirring gently, slowly pour the cream mixture into the hot sugar. BE CAREFUL with this step as the hot sugar will bubble up, doubling or tripling in size, and splatter.
5. Once the cream is added and the caramel mixture has calmed down, place it back over medium heat and bring to a boil. Use a candy thermometer to cook the caramel until it reaches soft ball stage - 235°F to 245°F. I like to take mine off the heat at 240°F. This ensures your caramel will have the perfect texture to set properly atop the cake.
6. Transfer the hot caramel to a heatproof bowl (like a metal mixing bowl) to cool. Once it has cooled a bit, you can go ahead and transfer it to a smaller jar or glass to easily pour later.

Make the Filling & Crumb Topping

1. For the filling, add the brown sugar, cinnamon, and flour in a small bowl; whisk until combined & set aside.
2. For the crumb topping, whisk together the brown sugar, flour, cinnamon, and chopped pecan pieces. Add the cold, cubed butter and use a fork (or your hands) to gently mash the butter into the mixture. You should end up with a crumb-like mix with some bigger chunks of butter. Set the crumb topping in the refrigerator (to keep the butter cold).

Make the Cake

1. Preheat your oven to 350°F and prepare a 9" springform pan (or 8x8" baking pan) by spraying it with nonstick spray and lining the bottom with parchment paper.
2. In a medium bowl, whisk together the flour, cornstarch, baking soda, and salt; set aside.
3. In a large bowl, beat together the butter and brown sugar until fluffy. Beat in the eggs, and then beat in the vanilla extract.
4. Add in 1/3 of the flour mixture and beat. Add 1/2 of the milk and beat. Repeat. Finally, add the last 1/3 of the flour mixture and beat until smooth.
5. Pour half of the cake batter into your prepared pan, smoothing out the top. Sprinkle the cinnamon filling over the batter. Scoop the remaining cake batter over the top of the filling, gently leveling and smoothing out the top - be careful not to mix the filling and batter.
6. Finally, sprinkle the crumb topping over the batter. Bake the cake at 350°F for 50-60 minutes or until a toothpick inserted into the cake comes out with a few crumbs.
7. Allow the cake to cool in the springform pan for 10 minutes before releasing and allowing to cool completely - I let mine cool on the bottom of the pan. If using an 8x8" pan, allow the cake to cool completely in the pan.
8. Once cooled, remove the cake from the pan and drizzle the caramel over the top of the cake. Some may drip down the side of the cake, so you may want to do this on a surface that can easily be cleaned. If the caramel is too thick to pour, heat it in the microwave in 10 second intervals until it's just thin enough to pour.
9. Store leftover cake in an airtight container at room temperature. Re-heat leftover cake and top with butter for an extra delicious slice.