Watch a video of me making the strawberry filling here. Add all the filling ingredients in a heavy-bottom saucepan.
Heat on medium-low until sugar melts and the strawberries release their juices. Cook until the mixture looks translucent or glossy, not opaque. Tip - cornstarch helps thicken the mixture but it is very important that the mixture becomes glossy, translucent, not opaque for the cornstarch to cook.
Cool completely before using. Divide as requested for the batter and filling
Dry ingredients - Combine flour, baking powder, baking soda, and salt - set aside.Tip - sifting the flour will give a light and airy cake
In the bowl of a stand mixer with the whisk attachment - whip eggs for a minute. Then gradually add the sugar until light and fluffy.Tip - Adding the sugar gradually will prevent the eggs from breaking down which gives a light and fluffy mixture.
Next, gradually add the oil followed by ⅓ of the strawberry filling.Tip - Add the oil gradually but not so slow or you will lose all the volume in the egg mixture.
Then, add the sour cream and a few drops of pink food color gel. Followed by the vanilla and strawberry extract. Combine well.
Finally, add the flour mixer - and combine well.Tip - you want to continue to use the whisk attachment to prevent lumps but do not overmix the batter.
Assemble and bake
Pour ⅓ of the cake batter into the prepared bundt pan - spread it over the sides and middle of the pan ( see video)
Then, add 4 tbsp of the strawberry filling keeping it within the batter away from the edges.Tip - we try to avoid the edges so the cake does not stick to the pan later. Putting the filling in a piping bag would be helpful.
Repeat with more cake batter and filling. Finally, top with cake batter on top.
Bake in the oven for about 50 to 60 minutes or until a skewer inserted in the center comes clean. Cool on a wire rack for at least 10 minutes before inverting.
To invert, place a plate on the pan and flip it. Cool completely then dust with powdered sugar (optional)