In a bowl, mix together tomatoes with olive oil and garlic. Let marinate for at least 1 hour.
Heat oven to 350°. Line a 9” x 13” pan with parchment paper and grease with butter; set aside. Whisk together flour, tomato powder, baking powder, and salt in a bowl; set aside. In a large bowl, beat butter and sugar on medium speed of a hand mixer until fluffy, about 3 minutes. Add eggs one at a time, beating after each addition until smooth. Add dry ingredients, and beat until just combined; slowly stream in the milk and mix until you have a smooth batter. Pour batter evenly into prepared pan; bake, turning halfway through, until dark orange in color, about 15 minutes. Let cool, then cut into rounds with a 3" cutter; you should get 11 rounds.
Using a stovetop smoker, lined with aluminum foil, smoke feta for 20 minutes, according to the manufacturer's instructions. Let feta cool, then transfer to a blender with the cream. Blend until smooth.
To assemble, place each cake round on a plate and top with 1 tablespoon smoked feta cream. Place 4 marinated cherry tomato halves, cut side down, on top of the cream. Garnish with fleur de sel.