Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the eggs one at a time, then stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined.
Pour the batter into the prepared cake pan and spread evenly.
In a separate small bowl, toss the chopped rhubarb with granulated sugar and almond extract.
Spoon the rhubarb mixture evenly over the cake batter.
Bake for 35-40 minutes, or until a wooden skewer inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely.
Notes
This cake is delicious served warm or at room temperature. It pairs wonderfully with a dollop of whipped cream or a scoop of vanilla ice cream.